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Background: Implant surface topography is a key element in achieving osseointegration. Nanostructured surfaces have shown promising results in accelerating and improving bone healing around dental implants. The main objective of the present clinical and histological study is to compare, at 4 and 6 weeks, (w) bone-to-implant contact in implants having either machined surface (MAC), sandblasted, large grit, acid-etched implant surface (SLA) medium roughness surface or a nanostructured calcium-incorporated surface (XPEED®). Methods: 35 mini-implants of 3.5 × 8.5 mm with three different surface treatments (XPEED® (n = 16)—SLA (n = 13)—MAC (n = 6), were placed in the posterior maxilla of 11 patients (6 females and 5 males) then, retrieved at either 4 or 6w in a randomized split-mouth study design. Results: The BIC rates measured at 4w and 6w respectively, were: 16.8% (±5.0) and 29.0% (±3.1) for MAC surface; 18.5% (±2.3) and 33.7% (±3.3) for SLA surface; 22.4% (±1.3) and 38.6% (±3.2) for XPEED® surface. In all types of investigated surfaces, the time factor appeared to significantly increase the bone to implant contact (BIC) rate (p < 0.05). XPEED® surface showed significantly higher BIC values when compared to both SLA and MAC values at 4w (p < 0.05). Also, at 6w, both roughened surfaces (SLA and XPEED®) showed significantly higher values (p < 0.05) than turned surface (MAC). Conclusions: Nanostructured Calcium titanate coating is able to enhance bone deposition around implants at early healing stages.

(1) Background: In the lateral area of the maxilla, the alveolar bone can lose significant volume due to maxillary sinus pneumatization following teeth extractions. This preliminary study evaluated the effectiveness of a novel technique for one-stage sinus lifting and simultaneous implant placement in cases with less than 1.5 mm residual alveolar bone. The subsequent survival rate at 1-year post-occlusal loading was assessed. (2) Methods: 15 patients were selected, the main inclusion criteria were the partially edentulous area in the posterior maxilla with alveolar bone height of less than 1.5 mm below the sinus. All of the patients underwent one-stage sinus lifting, along with simultaneous implant placement using a “butterfly” anchorage device to optimize the primary stability and xenograft bone as graft material. At 6 to 9 months after surgery, the anchorage device was removed and implants were loaded. Panoramic x-ray images were used to assess the new bone formation, while the biological stability was measured using resonance frequency analysis. (3) Results: 15 implants were inserted. The mean implant stability quotient (ISQ) value was 71.3 (SD = ±2.51) and the mean healing period was 7.3 (SD = ±1.23) months. The mean bone height after the healing period was 14.4 (SD = ±2.05). A statistically significant correlation was found between the healing period and the ISQ value (Spearman rho = 0.684, sig. = 0.005). No statistically significant correlation was found between the ISQ value and the new regenerated bone height (Person r = 0.389, sig. = 0.152). Smoking was identified as a risk factor involved in postoperative complications. (4) Conclusions: The results of the present preliminary study demonstrated that the proposed “butterfly” technique was effective when performing one-stage sinus lifting and simultaneous implant placement in cases with less than 1.5 mm of residual alveolar bone. The survival rate was 100% at 1-year post occlusal loading.

Pt-decorated In2O3 nanofibers with tailored size and morphology were synthesized as sensing materials for a highly sensitive toluene gas sensor. The bridge-type micro-platforms, including micro-heaters and micro-electrodes for the integration of In2O3 nanofibers-based sensing materials, were designed to demonstrate the sensing at high temperature with low power consumption. The gas sensing properties of the fabricated toluene gas sensor were systematically investigated by controlling the power of the micro-heater and the concentration of the toluene gas. Additionally, the enhanced sensing properties for various gas concentrations of toluene were investigated for Pt-nanoparticle-decorated In2O3 nanofibers.

Pt thin film temperature sensors (Pt T sensors) are embedded in micro gas sensors to measure and control the working temperature. We characterized electrical resistances of Pt T sensors and micro heaters with temperature changing in the oven and by Joule heating. In order to enhance the accuracy of temperature measurement by the Pt T sensors, we investigated the correlation among the Pt T sensor, micro heater, and the working temperature, which was linear proportional relation expressed as the equation: T2 = 6.466R1–642.8, where T2 = temperature of the Pt micro heater and R1 = the electrical resistance of the Pt T sensor. As the error by physically separated gap between Pt T sensor and micro heater calibrated, measuring and controlling temperature of micro heater in micro gas sensors were possible through the Pt T sensors. For the practical use of Pt T sensor in micro gas sensor, the gas sensing properties of fabricated micro gas sensors to 25 ppm CO and 1 ppm HCHO gases were characterized.

A capacitive-type touch sensor for detecting the touch position and touch load, simultaneously, is designed and manufactured using transparent electrode material. Generally, a touch sensor senses only the touch position. However, as the touch sensor proposed in this study is designed by separating the touch position and touch load sensing parts, it is possible to recognize the touch load, in addition to the touch position. The touch sensor is mainly composed of a polyethyleneterephthalate (PET) film substrate coated by an indium tin oxide (ITO), an ITO glass substrate, and a transparent elastomer. The ITO, as the transparent electrode, has an approximately 86% light transmittance and a sheet resistance of 30 Ω/square, and is patterned by photo-lithography process. A transparent elastomer, for load recognition, is sandwiched between the two transparent substrates and senses the magnitude of the touch load by detecting the change in capacitance value due to the change in the distance between the upper and lower electrodes, generated by the touch load. The fabricated touch sensor is 183 mm in width and 234 mm in length with a 10 in. touch area. It has 32 transmit lines for signal driving, 47 receive lines for signal detection, and two channels of ground lines. It can detect multi-touch with more than 10 points and sense loads up to 700 gf, simultaneously.

Background: Macro- and micro-geometry are among the factors influencing implant stability and potentially determining loading protocol. The purpose of this study was to test a protocol for early loading by controlling implant stability with the selection of fixtures with different thread depth according to the bone density of the implant site. Materials and Methods: Patients needing implant therapy for fixed prosthetic rehabilitation were treated by inserting fixtures with four different thread diameters, selected based on clinical assessment of bone quality at placement (D1, D2, D3, and D4, according to Misch classification). Final insertion torque (IT) and implant stability quotient (ISQ) were recorded at baseline and ISQ measurements repeated after one, two, three, and four weeks. At the three-week measurement (four weeks after implant replacement), implants with ISQ &gt, 70 Ncm were functionally loaded with provisional restorations. Marginal bone level was radiographically measured 12 months after implant insertion. Results: Fourteen patients were treated with the insertion of forty implants: Among them, 39 implants showing ISQ &gt, 70 after 3 weeks of healing were loaded with provisional restoration. Mean IT value was 82.3 &plusmn, 33.2 Ncm and varied between the four different types of bone (107.2 &plusmn, 35.6 Ncm, 74.7 &plusmn, 14.0 Ncm, 76.5 &plusmn, 31.1 Ncm, and 55.2 &plusmn, 22.6 Ncm in D1, D2, D3, and D4 bone, respectively). Results showed significant differences except between D2 and D3 bone types. Mean ISQ at baseline was 79.3 &plusmn, 4.3 and values in D1, D2, D3, and D4 bone were 81.9 &plusmn, 2.0, 81.1 &plusmn, 1.0, 78.3 &plusmn, 3.7, and 73.2 &plusmn, 4.9, respectively. Results showed significant differences except between D1 and D2 bone types. IT and ISQ showed a significant positive correlation when analyzing the entire sample (p = 0.0002) and D4 bone type (p = 0.0008). The correlation between IT and ISQ was not significant when considering D1, D2, and D3 types (p = 0.28, p = 0.31, p = 0.16, respectively). ISQ values showed a slight drop at three weeks for D1, D2, and D3 bone while remaining almost unchanged in D4 bone. At 12-month follow-up, all implants (39 early loading, 1 conventional loading) had satisfactory function, showing an average marginal bone loss of 0.12 &plusmn, 0.12 mm, when compared to baseline levels. Conclusion: Matching implant macro-geometry to bone density can lead to adequate implant stability both in hard and soft bone. High primary stability and limited implant stability loss during the first month of healing could allow the application of early loading protocols with predictable clinical outcomes.

Implants with deep thread depth have been developed for the purpose of increasing total implant surface area. However, effects of implant thread depth remain controversial. The aim of this study is to examine effects of thread depth on peri-implant tissues in terms of bone-implant contact (BIC), bone-implant volume (BIV), and hard and soft tissue dimensions using comprehensive analyses, including microcomputed tomography (micro-CT).Five beagle dogs received experimental intramandibular implants 3 months after removal of their premolars and first molars (PThere were no significant differences in resonance frequency test results between the two groups. Although radiographic analysis showed no group differences, micro-CT (P = 0.01) and histomorphometry (P = 0.003) revealed the DT group had significantly lower BIC values than the ST group at 4 weeks. However, by 8 weeks, BIC values of the two groups did not differ significantly. No significant differences in BIV or soft tissue height were observed between the two groups at either time point.DT implants showed no benefits over ST implants when inserted in dog mandibles.

The aim of the present study was to compare the survival, stability, and complications of immediately loaded implants placed in postextraction sockets and healed sites.Over a 2-year period, all patients presenting with partial or complete edentulism of the maxilla and/or mandible (healed site group, at least 4 months of healing after tooth extraction) or in need of replacement of nonrecoverable failing teeth (postextraction group) were considered for inclusion in this study. Tapered implants featuring a nanostructured calcium-incorporated surface were placed and loaded immediately. The prosthetic restorations comprised single crowns, fixed partial dentures, and fixed full arches. Primary outcomes were implant survival, stability, and complications. Implant stability was assessed at placement and at each follow-up evaluation (1 week, 3 months, and 1 year after placement): implants with an insertion torque (IT)45 N·cm and/or with an implant stability quotient (ISQ)70 were considered failed for immediate loading. A statistical analysis was performed.Thirty implants were placed in postextraction sockets of 17 patients, and 32 implants were placed in healed sites of 22 patients. There were no statistically significant differences in ISQ values between the 2 groups, at each assessment. In total, 60 implants (96.8%) had an IT ≥45 and an ISQ ≥70 at placement and at each follow-up control: all these implants were successfully loaded. Only 2 implants (1 in a postextraction socket and 1 in a healed site, 3.2%) could not achieve an IT ≥45 N·cm and/or an ISQ ≥70 at placement or over time: accordingly, these were considered failed for stability, as they could not be subjected to immediate loading. One of these 2 implants, in a healed site of a posterior maxilla, had to be removed, yielding an overall 1-year implant survival rate of 98.4%. No complications were reported. No significant differences were reported between the 2 groups with respect to implant failures and complications.Immediately loaded implants placed in postextraction sockets and healed sites had similar high survival and stability, with no reported complications. Further long-term studies on larger samples of patients are needed to confirm these results.

In the anterior regions, the resorption of the buccal bone after tooth extraction leads to a contraction of the overlying soft tissues, resulting in an esthetic problem, particularly with immediate implant placement. In the socket shield technique, the buccal root section of the tooth is maintained, to preserve the buccal bone for immediate implant placement. The aim of this prospective study was to investigate the survival, stability, and complication rates of implants placed using a "modified" socket shield technique.Over a 2-year period, all patients referred to a dental clinic for treatment with oral implants were considered for inclusion in this study. Inclusion criteria were healthy adult patients who presented nonrestorable single teeth with intact buccal periodontal tissues in the anterior regions of both jaws. Exclusion criteria were teeth with present/past periodontal disease, vertical root fractures on the buccal aspect, horizontal fractures below bone level, and external/internal resorptions. The buccal portion of the root was retained to prevent the resorption of the buccal bone; the shield was 1.5 mm thick with the most coronal portion at the bone crest level. All patients then underwent immediate implants. In the patient with a gap between the implant and shield, no graft material was placed. All implants were immediately restored with single crowns and followed for 1 year. The main outcomes were implant survival, stability, and complications.Thirty patients (15 males, 15 females; mean age was 48.2 ± 15.0 years) were enrolled in the study and installed with 40 immediate implants. After 1 year, all implants were functioning, for a survival rate of 100%; excellent implant stability was reported (mean implant stability quotient at placement: 72.9 ± 5.9; after 1 year: 74.6 ± 2.7). No biologic complications were reported, and the incidence of prosthetic complications was low (2.5%).The "modified" socket shield technique seems to be a successful procedure when combined with immediate implant placement, because the root fragment does not interfere with osseointegration and may be beneficial for the esthetics, protecting the buccal bone from resorption.

With the development of smart devices supporting VR (Virtual Reality) and AR (Augmented Reality), users' input devices are changing to wearable devices. The existing input devices for gesture recognition were relatively rigid. In this research, we propose a gesture recognition device by using a flexible substrate to manufacture a device that can be used in close contact with a user's wrist. An array of flexible resistive strain gauge sensors was fabricated for sensing spatial muscle movements of the wrist. The fabricated strain sensors showed a linearly varying output characteristic, and a sensitivity of 0.05143 Ω/g was obtained for a load test from 0 to 500 g. A circuit board for processing sensor data was fabricated and a program was coded for collecting the sensor data from the circuit board. With this system, it was confirmed that the average recognition rate per gesture is 94.6% after applying these input devices directly to five basic wrists gestures on five test subjects.

Intelligence Fusion cluster is a interdisciplinary program which consists of school of electrical, electronics, and communication, school of computer science and engineering, school of architecture and architectural engineering, and department of industrial design engineering. To make an effective management plan for intelligence fusion cluster, we surveyed students and faculty members who belong to the cluster. A management plan was derived based on this survey. The plan was presented in two ways: by curriculum improvement and research vitalization.

For keeping the safety of compressed natural gas-powered buses (CNG, CH4), a small sized and low power consumption gas sensor is needed for the fuel leakage alarm system. So catalytic combustible micro gas sensors were designed and fabricated by microelectromechanical systems (MEMS) technology and the sensors were measured output voltage potential of the sensor circuit as sensitivities to methane. The sensor was consisted of a sensing platform and a compensation platform, and the length and width of the fabricated platform were 3 mm by 3 mm. The output voltage of a fabricated micro sensor were 0.727 mV, 0.548 mV, 0.45 mV, and 0.29 mV at methane concentrations of 4,630 ppm, 3,473 ppm, 2,315 ppm, and 1,158 ppm respectively, at the input power of 104 mW. Fabricated micro gas sensors could be operated at low power consumption and showed good selectivity. For further study, the long-term stability of micro sensors will be done before applying to CNG powered buses.

We demonstrate a flexible strain-gauge sensor and its use in a wearable application for heart rate detection. This polymer-based strain-gauge sensor was fabricated using a double-sided fabrication method with polymer and metal, i.e., polyimide and nickel-chrome. The fabrication process for this strain-gauge sensor is compatible with the conventional flexible printed circuit board (FPCB) processes facilitating its commercialization. The fabricated sensor showed a linear relation for an applied normal force of more than 930 kPa, with a minimum detectable force of 6.25Pa. This sensor can also linearly detect a bending radius from 5mm to 100mm. It is a thin, flexible, compact, and inexpensive (for mass production) heart rate detection sensor that is highly sensitive compared to the established optical photoplethysmography (PPG) sensors. It can detect not only the timing of heart pulsation, but also the amplitude or shape of the pulse signal. The proposed strain-gauge sensor can be applicable to various applications for smart devices requiring heartbeat detection.

Background This study was to investigate the effect of collagen grafted porous biphasic calcium phosphate (BCP) on cell attachment, proliferation, and differentiation. Porous BCP scaffolds with interconnected micropore structure were prepared with were prepared and then grafted with a collagen type I. The hydroxyapatite (HA) and β-tricalcium phosphate (TCP) ratio of the TCP scaffolds was about 60/40 and the collagen was crosslinked on the TCP scaffold surface (collagen-TCP). Results The sintered BCP scaffolds showed fully interconnected micropore structures with submicron-sized grains. The collagen crosslinking in the scaffolds was conducted using the the N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide (NHS) crosslinking method. The cell proliferation of collagen-BCP scaffolds showed a similar result to that of the BCP scaffolds. However, osteoblastic differentiation and cell attachment increased in the collagen-BCP scaffolds. Conclusions Collagen-BCP scaffold improved the cell attachment ability in early phase and osteoblastic differentiation.

Calcium-incorporated titanium (Ti) recently reported a large degree of effectiveness in many in vitro and in vivo studies. The implants with the deeper thread provide the higher surface area and will have an advantage in soft bone. We used the Ti implants with deep threads and investigated osseintegration of the implants with resorbable blast media (RBM) surfaces produced by grit-blasting or XPEED surfaces by coating of the nanostrucutred calcium.The Ti implants with deep threads had a thread diameter of 4.0 mm, a length of 5.0 mm and a thread depth of 1.0 mm. The Ti implants with calcium-incorporated surfaces (XPEED surfaces) were hydrothermally prepared from the Ti implants with RBM surfaces in alkaline calcium containing solution. The surface characteristics were evaluated by using scanning electron microscope (SEM) and surface roughness measuring system. Thirty-implants with RBM surfaces and thirty-implants with XPEED surfaces were randomly placed in the proximal tibiae and in the femoral condyles of ten New Zealand White rabbits. The osseointegration was evaluated by removal torque test in the proximal tibiae and histomorphometric analysis in the femoral condyles. The Ti implants with XPEED surfaces showed a similar surface morphology and surface roughness to those of the Ti implants with RBM surfaces. The mean removal torque of the Ti implants with XPEED surfaces was higher than the Ti implants with RBM surfaces (p < 0.05). The percentage of bone-to-implant contact (BIC %) were increased for the Ti implants with XPEED surfaces compared with the Ti implants with RBM surfaces (p < 0.05).The Ti implants with XPEED surfaces significantly enhanced the removal torque and the BIC %. The Ti implants with XPEED surfaces may be shorten healing time of bone by improving osseointegration of Ti implants with deep threads.

A Micro platform for micro gas sensor consisted of micro heater, insulator, and sensing electrode on 2 uNthick SiN x membrane.Three types of micro platforms were designed and fabricated with membrane sizes. Total size of micro platform was 2.6 mm by 2.6 mm.Measured power consumptions were 28 mW, 28 mW, and 32.5 mW for Type 1, Type 2, and Type 3. At this moment, temperatures ofmembranes on the platforms were 295 \C, 297 \C, and 296 \C, respectively. Fabricated micro platform considered appropriate to applyfor low power consumption micro gas sensor. Micro gas sensors were prepared by the sequence that SnO 2 nanopowder pastes weredropped on membrane of Type 1 platforms, dried in oven, heat-treated with micro heaters in platforms. One of the micro gas sensors wastested for gas response to 1157 ppm, 578 ppm, and 231 ppm of methane and 1.68 ppm, 0.84 ppm, and 0.42 ppm of NO 2 . Keywords : MEMS, Micro Gas Sensor, Micro Platform, Low Power Consumption ² y > } a B A Ž : × > A ² ×b & @ ³ 2 : t E Þ PD A ² 3 2 & A Ž Þ × jI a A P 3 Ž Þ × j i I D ( ?8 «L uS i n A ² ENd 3 ? Þ t ENd D ( 3 u ýy o c± × E a8 Þ × O O ¬7 s O & @ 2 ‰ ³ 2 Þ × oI >N ‹ × n7y nI ³ : t u Ý 3 m × a uS ( þ × > > Þ c a i .&.4 •7I i M7 ~x8 > Þ Þ q Þ Ý x ™ A > A ² 3X Þ Ý$ c m O A FI Ž : » i O 3 \ ¯ CI u ýd 3 * ; NO D y A R o = ý ' ? Þ E ? a ƒ > ; 8 CI u ý™ i ³‘ ý ? Þ E u ý C 7 O Ð O ³5 ýC E ?, Ý a › > hN 3 a ƒ CI u ýd i ENy O8 ¯ eI ýX a ƒ CI u ýd 3 « ;I · X • A —Q Þ EX a ƒ >S i E ³ A ² ×.&.4 •8O i Þ E > A ² ýI a CI u ý O O ¬8‘ Þ Š CI u ý O O ¬D CI u ýd AK > : × × :y n — O O ¬o , a ( 3  Þ E ` ?8‘ Ž Þ O5 t > A ²Dx ?8 K Þ Ý$ c‘ ; CI u ý O O ¬ A ENd 3 ? Þ E CI u ý > A ² ýX Þ Š k —/0

Using mixed SnO2 nanoparticles with 1 wt.% MWCNTs sensing materials, NO2, NH3, and xylene gas sensors were fabricated on micro-platforms. A micro-platform consists of micro-sensing electrode and micro-heater on 2 μm thick SiNx membrane. The fabricated gas sensors were characterized to NO2, NH3, and xylene gases, respectively, as a function of concentration at 300 °C and temperature from 180 °C to 380 °C at constant concentration. The measured highest sensitivities for the NO2, NH3, and xylene were 1.06 at 1.2 ppm and 220 °C, 0.19 at 60 ppm, and 220 °C, and 0.15 at 3.6 ppm and 220 °C, respectively. So, it was found that 220 °C was the optimum temperature to have the best sensitivities. From these results, mixed SnO2 nanoparticles with 1 wt.% MWCNTs showed good sensitivity and selectivity at low power operation below 30 mW. Fabricated micro-gas sensors could be used for ubiquitous sensor network applications to monitor environmental pollutants in the air.

A polymer-based flexible tactile sensor array integrated with interconnection terminals was fabricated with polymer MEMS technologies and electroplating. The tactile sensing arrays were made as 4 × 4, 8 × 8, 16 × 16 and 32 × 32 sensing elements connected with a pluggable connector. Both the tactile sensor arrays and the interconnection terminals were fabricated together on the same polymer substrate in order to integrate them as a sensor module. The tactile sensor array with FFC (flexible flat cable) can be easily connected with the sensor array mounting PCB board by inserting the flexible cable into the pluggable connector socket on the board. The number and pitch of the fabricated interconnection terminals for 32 × 32 arrays were 68 and 500 μm, respectively. Continuous normal force ranging 0–1 N was applied to a unit tactile sensor for evaluating the tactile sensor characteristics through the integrated interconnection terminals. The measured resistance increased linearly with normal force in the range of 0–0.6 N but the resistance variation rate decreased above 0.6 N. The variation rate of the resistance is about 2.0%/N in the range of 0–0.6 N and 1%/N in the range of 0.6–1 N. The characterization of the tactile sensor array for the rod bar and a fingertip was successfully evaluated using the custom designed controller and the window-based 3D display software.

This paper is concerned with formability of AZ31B magnesium alloy sheets at various temperatures. In order to acquire the forming limit curve for quantifying the formability of the magnesium alloy sheet, hemispherical punch forming tests are performed under various temperatures. The initial shape of the blank is rectangular and six different types of specimens are used with their length along the rolling direction of 175mm and widths along the transverse direction of 25, 50, 75, 100, 120 and 175mm. With the equipment of on a SIMADZU 100-ton universal testing machine, hemispherical punch forming tests are performed and a forming limit diagram is constructed at the temperature of 100°C, 200°C and 250°C. FE analyses of hemispherical punch forming tests are also conducted by considering ductile failure model in order to compare the forming limit curve obtained from the experiment and numerical analysis. The comparison examines problems in the current material model and it suggests a future research direction.

The biocompatibility of calcium ion (Ca)-incorporated Ti6Al4V alloy implants, produced by hydrothermal treatment using a Ca-containing solution, was investigated. The surface characteristics were evaluated by scanning electron microscopy, thin-film X-ray diffractometry, Auger electron spectroscopy, and stylus profilometry. The viability of MC3T3-E1 cells on Ca-incorporated machined Ti6Al4V surfaces with different oxide thicknesses was compared with that on untreated machined Ti6Al4V surfaces with MTT assay. The osteoconductivity of the Ca-incorporated Ti6Al4V implants was evaluated by removal torque testing and histomorphometric analysis after 6 weeks of implantation in rabbit tibiae. Our results show that hydrothermal treatment with a Ca-containing solution produced a crystalline CaTiO(3) layer on Ti6Al4V surfaces, and calcium ions were gradually incorporated throughout the oxide layer. After immersion in Hank's balanced salt solution, a considerable apatite deposition was observed on all surfaces of the Ca-incorporated samples. Significant increases in cell viability (p0.001), removal torque forces, and bone-to-implant contact values (p0.05) were observed for Ca-incorporated Ti6Al4V implants compared with those for untreated Ti6Al4V implants.

A force sensing touchscreen, which detects touch point and touch force simultaneously by sensing a change in electric capacitance, was designed and fabricated. It was made with single-walled carbon nanotubes (SWCNTs) which have better mechanical and chemical characteristics than the indium-tin-oxide transparent electrodes used in most contemporary touchscreen devices. The SWCNTs, with a transmittance of about 85% and electric conductivity of 400 Ω per square; were coated and patterned on glass and polyethyleneterephthalate (PET) film substrates. The constructed force sensing touchscreen has a total size and thickness of 62 mm × 100 mm × 1.4 mm, and is composed of 11 driving line and 19 receiving line channels. The gap between the channels was designed to be 20 µm, taking visibility into consideration, and patterned by a photolithography and plasma etching processes. The mutual capacitance formed by the upper and lower transparent electrodes was initially about 2.8 pF and, on applying a 500 gf force with a 3 mm diameter tip, it showed a 25% capacitance variation. Furthermore, the touchscreen can detect multiple touches and forces simultaneously and is unaffected by touch material characteristics, such as conductance or non-conductance.

Recently a submicron particle of biphasic calcium phosphate ceramic (BCP) with through-hole (donut-shaped BCP (d-BCP)) was developed for improving the osteoconductivity. This study was performed to examine the usefulness of d-BCP for the delivery of osteoinductive rhBMP2 and the effectiveness on cranial bone regeneration. The d-BCP was soaked in rhBMP2 solution and then freeze-dried. Scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and Raman spectroscopy analyses confirmed that rhBMP2 was well delivered onto the d-BCP surface and the through-hole. The bioactivity of the rhBMP2/d-BCP composite was validated in MC3T3-E1 cells as anin vitromodel and in critical-sized cranial defects in C57BL/6 mice. When freeze-dried d-BCPs with rhBMP2 were placed in transwell inserts and suspended above MC3T3-E1, alkaline phosphatase activity and osteoblast-specific gene expression were increased compared to non-rhBMP2-containing d-BCPs. For evaluatingin vivoeffectiveness, freeze-dried d-BCPs with or without rhBMP2 were implanted into critical-sized cranial defects. Microcomputed tomography and histologic analysis showed that rhBMP2-containing d-BCPs significantly enhanced cranial bone regeneration compared to non-rhBMP2-containing control. These results suggest that a combination of d-BCP and rhBMP2 can accelerate bone regeneration, and this could be used to develop therapeutic strategies in hard tissue healing.

An integrated microammonia analysis system (IMAAS) with microreactor and in-plane ( x -axis) type optical source and optical detector with ease and precise optical alignment method using microchannels for optical fiber guide by silicon deep RIE process based on the Berthelot reaction was newly proposed and investigated. It is not necessary to do difficult and complex optical alignment process for ammonia analysis than the case of using out-of-plane ( z -axis) type optical detector perpendicular to microfluidic devices. The proposed IMAAS with the size of 5 cm × 5 cm and thickness of 1 mm was fabricated using typical and simple MEMS processes. IMAAS was packaged with inlet and outlet tube, and optical fiber connected with in-plane type optical source and optical detector using UV epoxy bonding. Reaction rates from ammonia of the concentration of 16.5 ppm to indophenols at IMAAS were remarkably increased with temperatures from 308 to 318 K on hot plate as a heater. In case of reaction temperature of 318 K, complete reaction time was less than 1 min. Reaction rates were increased with ammonia concentrations from 4.1 to 33.0 ppm at the temperatures of 308, 313 and 318 K. In order to remarkably decrease total analysis system, thermoelectric heater of 2 cm × 2 cm was used as a heater. In case of using thermoelectric heater at the temperature of 308 K and the ammonia concentration of 2 ppm, the complete reaction time of indophenol in IMAAS was in the range of 100–150 s. From these results, IMAAS on thermoelectric heater has advantage for small size and local heating of reaction region in IMAAS than the case of using hot plate heater. Fabricated IMAAS were reproducible and suitable for the determination of ammonia concentrations. For the future works, it was thought these microsystems could be used for other microreactions for versatile species analyses as well as detections for N-containing organic species.

We present the fabrication process and characteristics of a 3-axes flexible tactile sensor available for normal and shear mode fabricated using Si micromachining and packaging technologies. The fabrication processes for the 3 axes flexible tactile sensor were classified in the fabrication of sensor chips and their packaging on the flexible PCB. The variation rate of resistance was about 2.1%/N and 0.5%/N in applying normal and shear force, respectively. Because this tactile sensor can measure the variations of resistance of the semiconductor strain gauge for normal and shear force, it can be used to sense touch, pressure, hardness, and slip.

Recently, many researchers have been attempted to reduce the power consumption in the sensor system and to increase the sensitivity for toxic gases. Most metal oxide sensing films are deposited on an alumina substrate which is easy process but needs high power consumption. Moreover, thin film sensor deposited on the Si substrate shows low sensitivity. Accordingly, this study investigated the fabrication of thick film gas sensors based on tin oxide on a Si substrate. Two heater shapes using a micro electro mechanical system (MEMS) are designed and simulated, and their gas response characteristics to test gases were examined. The sensing materials are SnO2 mixed with Al2O3, and test gases are CH2Cl2, CH3CN as simulant chemical warfare agents. Consequently, high sensitivity is acquired by using a thick sensing film and low power consumption is achieved by using MEMS technology.

Design and fabrication of micro mixing cells and detection cells were investigated. Glass micro mixing cells with island structures among channels were fabricated using sand blaster methods. Depth and width of mixing channel were 200 ㎛ and 180 ㎛ and island size was 90 ㎛ by 90 ㎛. Two 45° mirrors surfaces faced on each other in one detection cell which were fabricated by silicon anisotropic etching using 20% TMAH (Tetramethylammonium hydroxide) solution with 20% or 30% IPA (iso propyl alcohol) at 80°C, respectively. Up side glass wafer for mixing cell and down side silicon wafer for detection cell were bonded using anodic bonding method at 350ı, -600 V and 300 N. Synthetic indophenol was injected at inlet and moved to the detection cell through the mixing channel. HeNe laser of 632.8 nm was focused on one side of a 45° mirror, and passed through indophenol solution until the other side of a 45° mirror. The light of 632.8 nm was absorbed in indophenol solution between two 45° mirrors at detection cell. By the Beer-Lambert’s law, indophenol concentration could be calculated from the measured result of the absorbance.

The eight types of micro-grippers with silicon were simulated by ANSYS and fabricated by MEMS(Micro Electro Mechanical System) process. Each type of micro-grippers had a small difference in design shape such as beam width, gap between beams. In order to modify design shape, these micro-grippers were estimated and simulated in point of structure, actuation characteristics by changing design factors. Micro-grippers were composed of five parts which were piezoelectric actuation part, fixing part, rotation arms, the block and gripping jaws. The shape of gripping jaws was designed as the teeth of a saw to reduce adhesion force by decreasing the contact area. The 10.2 µm movement by piezoelectric actuator at 120 V generated the 142.8 µm gripping range of a micro-gripper in real measurement. In the case of simulation result, the gripping range of 162 µm was generated at the same condition. This gripping range was enough to handle small objects like micro-parts

PURPOSE This study aimed to evaluate the effect of implant thread depth on primary stability in low density bone. MATERIALS AND METHODS The insertion torque was measured by inserting Ti implants with different thread depths into solid rigid polyurethane blocks (Sawbones) with three different bone densities (0.16 g/cm3, 0.24 g/cm3, and 0.32 g/cm3). The insertion torque value was evaluated with a surgical engine. The static compressive strength was measured with a universal testing machine (UTM) and the Ti implants were aligned at 30° against the loading direction of the UTM. After the static compressive strength test, the Ti implants were analyzed with a Measurescope. RESULTS The Ti implants with deeper thread depth showed statistically higher mean insertion torque values (P.05). After the static compressive strength, the thread shape of the Ti implants with deeper thread depth did not show any breakage but did show deformation of the implant body and abutment. CONCLUSION The implants with deeper thread depth had higher mean insertion torque values but not lower compressive strength. The deep threads had a mechanical stability. Implants with deeper thread depth may increase the primary stability in areas of poor quality bone without decreasing mechanical strength.

MEMS six-element array platforms (MAP) with low power consumption for micro/nano gas sensors were newly designed, fabricated and characterized. The total size of MAPs was same as 8 mm by 12mm. Five samples of MAPs were designed with ratios of SiN x membrane areas to Pt heater areas 7.14(sample 1), 10.90(sample 2), 13.63(sample 3), 16.51(sample 4), and 19.51(sample 5). Good linearity of temperatures from 300 degree C to 625 degree C with increasing input power consumptions of individual elements of MAPs was shown. Power consumptions of five samples were in the range of about 58∼62 mW at 300 degree C measured at the center of membranes of MAPs. At different applied voltages to micro heaters for all six elements of a MAP sample, they showed good temperature uniformity. It was thought that the suggested MAP could be used for portable micro/nano gas sensor arrays for detection and discrimination mixture gases, simultaneously.

In this study, we prepared adriamycin (ADR)-encapsulated nanoparticles using deoxycholic acid-conjugated dextran (DexDA). Its antitumor activity was evaluated using CT 26 tumor cells in vitro and in vivo. ADR-incorporated DexDA nanoparticles have spherical shapes and their particle sizes were ranged about 50-200. Their particle sizes were changed according to the preparation conditions, i.e., the higher substitution degree (DS) of deoxycholic acid (DA) and higher drug feeding ratio induced increased particle size and zeta potential. Furthermore, the higher DS of DA and higher drug feeding ratio induced increased drug contents and loading efficiency of drug. The higher DS of DA and higher drug feeding ratio induced decreased drug release rate. Futhermore, acidic pH of release media accelerated the drug release rate compared to alkaline pH. At in vitro cytotoxicity test using CT26 tumor cells, the nanoparticles showed higher antitumor activity than free ADR. In fluorescence microscopic observation, nanoparticles were properly entered into tumors cells and maintained in the cells compared to ADR itself. At in vivo animal tumor model using CT-26 cells, nanoparticles resulted in survivability increase of mice even though free ADR showed higher effectiveness to inhibit tumor growth. These results suggested that ADR-incorporated DexDA nanoparticles are promising vehicles for anti-tumor drug delivery.

This study evaluated cytocompatibility and osseointegration of the titanium (Ti) implants with resorbable blast media (RBM) surfaces produced by grit-blasting or XPEED(®) surfaces by coating of the nanostructured calcium.Ti implants with XPEED(®) surfaces were hydrothermally prepared from Ti implants with RBM surfaces in a solution containing alkaline calcium. The surface characteristics were evaluated by using a scanning electron microscope (SEM) and surface roughness measuring system. Apatite formation was measured with SEM after immersion in modified-simulated body fluid and the amount of calcium released was measured by inductively coupled plasma optical emission. The cell proliferation was investigated by MTT assay and the cell attachment was evaluated by SEM in MC3T3-E1 pre-osteoblast cells. Thirty implants with RBM surfaces and 30 implants with XPEED(®) surfaces were placed in the proximal tibiae and in the femoral condyles of 10 New Zealand White rabbits. The osseointegration was evaluated by a removal torque test in the proximal tibiae and by histomorphometric analysis in the femoral condyles 4 weeks after implantation.The Ti implants with XPEED(®) surfaces showed a similar surface morphology and surface roughness to those of the Ti implants with RBM surfaces. The amount of calcium ions released from the surface of the Ti implants with XPEED(®) surfaces was much more than the Ti implants with RBM surfaces (P0.05). The cell proliferation and cell attachment of the Ti implants showed a similar pattern to those of the Ti implants with RBM surfaces (P0.1). Apatite deposition significantly increased in all surfaces of the Ti implants with XPEED(®) surfaces. The removable torque value (P = 0.038) and percentage of bone-to-implant contact (BIC%) (P = 0.03) was enhanced in the Ti implants with XPEED(®) surfaces.The Ti implants with XPEED(®) surfaces significantly enhanced apatite formation, removal torque value, and the BIC%. The Ti implants with XPEED(®) surfaces may induce strong bone integration by improving osseointegration of grit-blasted Ti implants in areas of poor quality bone.

In order to increase biocompatibility, many dental implants have been studied by immobilization of biomolecules on biomaterials. We used l-3,4-dihydroxyphenylalanine (L-DOPA) as a biomolecule for surface-modified titanium. Water contact angles of nontreated titanium discs (negative control), etched titanium discs (positive control), and titanium discs treated with L-DOPA following the etching process (experimental group) were 82.4 ± 5.7°, 67.1 ± 0.56°, and 44.15 ± 0.91°, respectively. Using atomic force microscopy images, we were able to find L-DOPA, which adhered to the titanium surface. The number of human bone marrow mesenchymal stem cells (BM-MSCs) in the experimental group was much higher than that of cells in any other group. Quantification values of amine groups in the positive control and experimental groups were approximately 3 and 7.5 µg, respectively. Therefore, findings from our research suggested the possibility of a causal link between increased L-DOPA content and cell proliferation in BM-MSCs. Moreover, coating of the discs with L-DOPA can result in greater hydrophilicity of the titanium surface and enhancement of cell adhesion and mitochondrial activity .

Objectives: This study investigated the efficacy of new bone graft substitutes – biphasic calcium phosphates (BCP) made of submicron-sized grains with fully interconnected wide-range micron-scale pores in two different macrodesigns: donut shaped with a 300–400 μm central macropore (n-BCP-1) or rod-shaped (n-BCP-2) – in the healing of rabbit calvarial defects, and compared their bone-healing properties with those of various commercial bone substitutes, which included substitutes with similar BCP composition (MBCP and Osteon), anorganic bovine bone (Bio-Oss), and β-TCP (Cerasorb). Material and methods: The surface morphology of the bone substitutes was investigated using scanning electron microscopy (SEM). Defects 8 mm in diameter were created in the calvaria of 30 adult male New Zealand White rabbits and were filled with six types of bone substitutes. The percentage of newly formed bone (NB%) was evaluated histomorphometrically 4 and 8 weeks after implantation. Results: SEM observation showed submicron-sized grains with fully interconnected micropore structures in the n-BCP-1 and n-BCP-2 groups; these groups also showed considerable new bone formation in inner micropores as well as on the outer surfaces. The n-BCP-1 group exhibited enhanced new bone formation and direct ingrowth of bone tissue with blood vessels into central pores. Histomorphometric analysis showed significantly greater NB% in the n-BCP-1 group when compared with the other groups at 4 and 8 weeks (P

A novel protocol for the synthesis of biocompatible and degradation controlled poly(lactic-co-glycolic acid) grafted hyaluronic acid (HA-PLGA) was successfully developed for periodontal barrier applications. HA was chemically modified with adipic acid dihydrazide (ADH) in the mixed solvent of water and ethanol, which resulted in a high degree of HA modification up to 85 mol.%. The stability of HA-ADH to enzymatic degradation by hyaluronidase increased with ADH content in HA-ADH. When the ADH content in HA-ADH was higher than 80 mol.%, HA-ADH became soluble in dimethyl sulfoxide and could be grafted to the activated PLGA with N,N'-dicyclohexyl carbodiimide and N-hydroxysuccinimide. The resulting HA-PLGA was used for the preparation of biphasic periodontal barrier membranes in chloroform. According to in vitro hydrolytic degradation tests in phosphate buffered saline, HA-PLGA/PLGA blend film with a weight ratio of 1/2 degraded relatively slowly compared to PLGA film and HA coated PLGA film. Four different samples of a control, OSSIX(TM) membrane, PLGA film, and HA-PLGA/PLGA film were assessed as periodontal barrier membranes for the calvarial critical size bone defects in SD rats. Histological and histomorphometric analyses revealed that HA-PLGA/PLGA film resulted in the most effective bone regeneration compared to other samples with a regenerated bone area of 63.1% covering the bone defect area.

A flexible tactile sensing module with NiCr strain gauges as sensing elements was fabricated by polymer MEMS technology using polyimide materials where the one was the photo-definable polyimide precursor and the other was nonphoto- definable. The unit sensor cell size of 32×32 tactile sensor array was 1mm × 1mm cell and its overall size was 5.5cm × 6.5cm. Especially, both the tactile sensor arrays and the pluggable terminals as flexible flat cable were fabricated on the same polymer substrate easily to be connected the sensor array with a PCB board. The fabricated tactile sensing module was measured continuously in the normal force range of 0~1N with tactile sensor evaluation system. The value of resistance was relatively linear with normal force in the overall range of 0~1N. However, the variation of resistance was decreased by more than 0.6N. The variation rate of resistance was 2.0%/N in the range of 0~0.6N and 1.5%/N in the range of 0.6~1N. Image display was identified corresponding by distribution of applied force. The flexibility of the sensing module was adequate to be placed on any curved surface as a cylinder.

We present fabrication of flexible tactile sensing module with NiCr strain gauge as sensing element and interconnecter for signal treatment by polymer MEMS (micro electro mechanical system) technologies using polyimide materials. The tactile sensor array is composed of 16 times 16 sensing elements with 2 mm times 2 mm cell size and its overall size is 4 cm times 5 cm. Both the tactile sensor array and interconnecter are placed in the sensing module during the fabrication process. The fabricated tactile sensing module is measured continuously in the normal force range of 0~1 N with tactile sensor evaluation system. The variation of resistance is relatively increased linearly in the range of 0~0.6 N and saturated after 0.6 N. The variation rate of resistance is approximately 3%/N in the linear range. In addition, the flexibility of the sensing module is adequate to be placed on any curved surface like cylinder because the matrix consists of polymer and metal thin film.

This letter reports the fabrication of polycrystalline silicon thin-film transistors (poly-Si TFT) on glass substrates using Al oxide films by anodizing. The a-Si films were deposited with mixture gas of argon and helium to minimize the argon incorporation into the film. The a-Si films were then laser crystallized using XeCl excimer laser irradiation and a four-mask-processed poly-Si TFTs were fabricated with fully self-aligned top gate structure.

We present the fabrication process and the characteristics of a flexible tactile sensor by silicon micromachining, polymer processing and packaging technologies. The fabrication process for the tactile sensor was composed of in the fabrication of sensor chips and their packaging on the flexible printed circuit board (FPCB). The variation rate of resistance was about 4.6%/N when normal force was applied. This sensor can be used to sense touch, pressure, and slip because the signals are is are determined by the variations of resistance of the metal strain gauge for normal and shear force in tactile sensor.

This letter reports the fabrication of Si nanowire using nanoimprint Method. We propose silicon nanowire fabricate method which enables us to provide mass production compatible and electronics device. The a-Si films were deposited with mixture gas of argon and helium to minimize the argon incorporation into the film. The a-Si films were then laser crystallized using XeCl excimer laser irradiation and nanoimprint processed was fabricated with quartz mask.

Integrated micro ammonia analysis systems (IMAAS) with micro reactor and in-plane type optical detector using Berthelot reaction and micro fluidic devices were newly proposed and investigated. IMAAS with the size of 5 cm by 5 cm and thickness of 1 mm were fabricated using MEMS processes. IMAAS were packaged with inlet and outlet tube, and optical fiber connected with in-plane type optical source and optical detector using UV epoxy bonding. Reaction rates from ammonia to indophenols at IMAAS were increased with temperatures. In case of reaction temperature of 318 K, reaction time was less than 1 min. From these results, fabricated IMAAS were reproducible and suitable for ammonia analysis. For the future works, it was thought these micro systems could be used for other micro reactions for versatile species analyses as well as detections for N-containing organic species including ammonia.

In this paper we present a micromirror fabrication technique without using silicon-on-insulator (SOI) wafers. Torsional electrostatic micromirrors have been fabricated using a combination of chemical mechanical polishing (CMP) process and anodic bonding. The size of fabricated silicon mirror plate was 610x400 μm 2 and 20 μm thick. The steering electrodes have been fabricated in the dry etched trench on the glass wafer by electroplating process and CMP processing without damage of electrodes during anodic bonding process. The surface roughness of polished silicon micromirror(Ra) was 3.19nm. The single crystal silicon mirrors are electrostatically actuated with parallel bottom electrodes placed 8 μm below the mirror plate, and they could be stably operated in a ±1.1°. The pull-in voltage has been measured as 520 V. The resonant frequency of the fabricated torsion mirror was 47.3 kHz.

A PMS consists of LED array, lens, polygon-mirror, and motor. A PMS's light sources is the linear LED array. We have fabricated a 400 dpi LED array using GaAs/AlGaAs (Al/spl sim/0.65) single heterojunction structure. Problems of AlGaAs LED arrays are among the emitters. Thus, we have performed isolation by RIE and wet etching. RIE experiments were carried out at room temperature and used a mixture of gases under a variety of etching conditions. The n and p ohmic contacts were made with AuGe/Ni/Au and AuZn/Pd/Au, respectively. The AlGaAs LED array showed good quality with low forward turn-on voltages and high brightness.