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Continuous glucose monitoring (CGM) allows patients with diabetes to manage critical disease effectively and autonomously and prevent exacerbation. A painless, wireless, compact, and minimally invasive device that can provide CGM is essential for monitoring the health conditions of freely moving patients with diabetes. Here, we propose a glucose-responsive fluorescence-based highly sensitive biodegradable microneedle CGM system. These ultrathin and ultralight microneedle sensor arrays continuously and precisely monitored glucose concentration in the interstitial fluid with minimally invasive, pain-free, wound-free, and skin inflammation–free outcomes at various locations and thicknesses of the skin. Bioresorbability in the body without a need for device removal after use was a key characteristic of the microneedle glucose sensor. We demonstrated the potential long-term use of the bioresorbable device by applying the tether-free CGM system, thus confirming the successful detection of glucose levels based on changes in fluorescence intensity. In addition, this microneedle glucose sensor with a user-friendly designed home diagnosis system using mobile applications and portable accessories offers an advance in CGM and its applicability to other bioresorbable, wearable, and implantable monitoring device technology.

오늘날 소비자들은 안전한 성분으로 만들어진 제품에 대한 관심이 높아지면서 화장품 시장에서는 비건 인증을 받은 화장품들이 증가하고 있다. 이러한 현상에서 소비자들은 안전한 성분으로 만들어진 제품에 대한 니즈를 충족시키기 위해 소셜미디어 및 애플리케이션 등의 다양한 콘텐츠를 활용하여 화장품 성분을 분석하거나 제품에 대한 정보를 제공 받고 있다. 하지만, 비건 화장품을 선호하는 소비자들은 비건 화장품에 대한 정보를 한곳에서 확인할 수 있는 콘텐츠가 부족하며, 자신이 선택한 화장품을 사용했을 때 피부에 어떠한 효과를 미치는지 알 수 없어 자신에게 맞는 비건 화장품을 구매하는 데 어려움이 있다. 이에 따라서, 본 연구는 국내 뷰티 서비스 시장을 살펴보고 변화된 현 시대적 상황에 따라 증가된 비건 화장품 시장에 맞춰서 활용할 수 있는 화장품 매칭 애플리케이션의 개발을 중심으로 시작되었다. 본 연구의 목적은 비건 화장품 매칭 애플리케이션을 사용하는 사용자들에게 제품의 정보 제공과 구매의 편의를 충족시킬 수 있는 서비스 방향을 제시하는 데 하는 것이다. 기존 출시된 화장품 애플리케이션의국. 내외 사례 분석과 비건 화장품 애플리케이션의 서비스 기능에 대한 소비자 요구를 반영하여 서비스 프로세스를 설계하여 개발하였다. 또한 실행 단계에서 사용자 심층 인터뷰를 진행하였던 대상에게 콘텐츠, 디자인, 시스템 항목으로 구분하여 사용자 조사를 시도하였다. 연구의 결과는 다음과 같다. 첫째, 향후 사용자 조사를 진행한 결과에서 보인 피부 타입별 테스트의 간결함과 단계별 접근성 등의 추가적인 개선 사항들을 충족할 수 있는 새로운 방법이 연구되어야 하며, 더 많은 비건 화장품과 피부 테스트 결과의 데이터를 축적하여 피부타입에 맞는 화장품 매칭 서비스의 정확성을 높여야 한다. 둘째, 사용자들은 비건에 대한 정보를 교류할 수 있으며, 중·장기적인 피부관리를 통해 소비를 가능하게 하는 새로운 방식의 서비스 방법을 제시하였다. 이러한 연구를 바탕으로 사용자들에게 구매에 대한 편의와 삶의 질을 높일 수 있는 가치 있는 온라인 뷰티 소비 공간을 제공해 줌으로써, 비건 매칭 서비스 개발이 향후 새로운 소비 방식에 대한 대안적인 방법으로 모색되었으며 비건 뷰티 소비시장의 확장에 이바지할 수 있기를 기대한다.

During the early phase of coronavirus disease 2019 (COVID-19) pandemic, South Korea was among the countries affected by the novel infectious disease soon after China. A year later, South Korea is considered one of the countries to have successfully responded to COVID-19. Even though South Korea has struggled to learn how to live wisely with COVID-19, much less effort has been put into learning how to die gracefully during the COVID-19 pandemic. From the beginning of the pandemic, the Korean government has recommended (or mandated) cremation for those who die from COVID-19 to prevent further spread of the disease. However, the World Health Organization has announced that corpses are generally not contagious and cremation should be a matter of culture choice and available resources. In South Korea, the government pays compensation to the families of the deceased because they follow the national guidelines for the cremation and disinfection of bodies. However, it is now time to discuss how to support the families of the deceased, helping them to safely grieve and honor their loved one in their own ways, rather than forcing them to wrap the deceased with a plastic bag and proceed with a hasty cremation.

Background Many features of health care organizations (HCOs) have been identified to be associated with health information exchange (HIE), but subcategories of organizational factors focusing on nurse workforces still need to be identified. The objective of this study is to investigate the association of number of nurses with HIE use in Korea. Methods This study had a retrospective study design and used health insurance claim data from June 1, 2016 to June 30, 2018. The unit of analysis was the HCO, and any health insurance claims having HIE were counted by HCO. There were a total of 1490 HCOs having any HIE and 24 026 HCOs not having HIE. For statistical analysis, two-part model was used: logistic regression for HIE participation and the generalized linear model for the volume of HIE use. Results HIE was used by 44.6% of general hospitals, and 8.6% and 5.3% of small hospitals and clinics, respectively. Both HIE use and its volume were significantly positively associated with nurse variables. The use of HIE was significantly positively associated with nurse-to-bed ratio in general hospitals (OR 1.028; 1.016 to 1.041) and in small hospitals (OR 1.021; 1.016 to 1.027), and with the number of nurses (OR 1.041; 1.028 to 1.054) in clinics (PConclusion This study found that there was a low rate of HIE use in small hospitals and clinics. The number of nurses was critically associated with the use of HIE and the volume of HIE claims. HIE policy makers need to be aware of this factor in seeking to accelerate HIE.

Epitaxial synthesis of inorganic nanomaterials on pristine 2D materials is of interest in the development of nanostructured devices and nanocomposite materials, but is quite difficult because pristine surfaces of 2D materials are chemically inert. Previous studies found a few exceptions including AuCN, AgCN, CuCN, and Cu0.5Au0.5CN, which can be preferentially synthesized and epitaxially aligned onto various 2D materials. Here, we discover that Au1/2Ag1/2CN forms diamond-shaped nanocrystals epitaxially grown on pristine graphene surfaces. The nanocrystals synthesized by a simple drop-casting method are crystallographically aligned to lattice structures of the underlying graphene. Our experimental investigations on 3D structures and the synthesis conditions of the nanocrystals imply that the rhombic 2D geometries originate from different growth rates depending on orientations along and perpendicular to 1D molecular chains of Au1/2Ag1/2CN. We also perform in situ TEM observations showing that Au1/2Ag1/2CN nanocrystals are decomposed to Au and Ag alloy nanocrystals under electron beam irradiation. Our experimental results provide an additional example of 1D cyanide chain families that form ordered nanocrystals epitaxially aligned on 2D materials, and reveal basic physical characteristics of this rarely investigated nanomaterial.

Prediction of outcome after stroke may help clinicians provide effective management and plan long-term care. We aimed to develop and validate a score for predicting good functional outcome available for hospitals after ischemic stroke using linked data. A total of 22,005 patients with acute ischemic stroke from the Clinical Research Center for Stroke Registry between July 2007 and December 2014 were included in the derivation group. We assessed functional outcomes using a modified Rankin scale (mRS) score at 3 months after ischemic stroke. We identified predictors related to good 3-month outcome (mRS score ≤ 2) and developed a score. External validations (geographic and temporal validations) of the developed model were performed. The prediction model performance was assessed using the area under the receiver operating characteristic curve (AUC) and the calibration test. Stroke severity, sex, stroke mechanism, age, pre-stroke mRS, and thrombolysis/thrombectomy treatment were identified as predictors for 3-month good functional outcomes in the S-SMART score (total 34 points). Patients with higher S-SMART scores had an increased likelihood of a good outcome. The AUC of the prediction score was 0.805 (0.798–0.811) in the derivation group and 0.812 (0.795–0.830) in the geographic validation group for good functional outcome. The AUC of the model was 0.812 (0.771–0.854) for the temporal validation group. Moreover, they had good calibration. The S-SMART score is a valid and useful tool to predict good functional outcome following ischemic stroke. This prediction model may assist in the estimation of outcomes to determine care plans after stroke.

We present a one-step method to fabricate microparticles to detect substances and release drugs in our bodies. Our microparticles have two compartments and an outer shell. The two compartments (Janus cores) enable the encapsulation of different materials separately for diagnosis and therapy while the outer shell reduces the adhesion and protects the encapsulated materials. These multi-functional core-shell Janus microparticles are fabricated by simply ejecting pre-gel solutions into a calcium chloride solution under centrifugal gravity application and UV irradiation. Moreover, we implanted these microparticles in biological tissue and demonstrated the transdermal sensing and drug model release. We believe that our fabrication method and particle design could be an effective approach for multi-functional smart theranostic medicine.

This work proposes a 3D lithography technique with self-focusing during polymerization based on refractive-indices change of polyethylene glycol diacrylate (PEGDA) (Fig. 1). Compared to the previous work, the present work enables to fabricate 3D structures using single UV exposure and theoretically estimate 3D features. We demonstrate the potential of the self-focusing 3D lithography by fabricating PEGDA microneedles and trapezoid-shaped wells. Their structures well match to our theoretical estimation. Therefore, our theoretical approach shows its potential for on-demand, complicated 3D structures of refractive-indices-variable materials with single UV exposure.

Gyeonggi-do (Gyeonggi province) has the second highest number of coronavirus disease (COVID-19) cases in the Republic of Korea after Seoul, with approximately 25% of the COVID-19 patients as of January 2021. Our center is a level I trauma center located in south Gyeonggi-do, and we aimed to evaluate whether the characteristics of trauma patients changed after the COVID-19 pandemic. We retrospectively reviewed the trauma patients registered with the Korea Trauma Database of the Center from February 2019 to January 2021. The patients were dichotomized into pre-coronavirus disease (pre-COVID) and coronavirus disease (COVID) groups, and their trauma volumes, injury characteristics, intentionality, and outcomes were compared. A total of 2628 and 2636 patients were included in the pre-COVID and COVID groups, respectively. During the COVID-19 period, motorcycle accidents, bicycle accidents, and penetrating injury cases increased, and pedestrian traffic accidents, slips, and injury by machines decreased. The average daily number of patients in the COVID group was lower in March (5.6 ± 2.6/day vs 7.2 ± 2.4/day, P = .014) and higher in September (9.9 ± 3.2/day vs 7.7 ± 2.0/day, P = .003) compared to the pre-COVID group. The COVID group also had a higher ratio of direct admissions (67.5% vs 57.2%, P

Continuous glucose monitoring (CGM) sensors have led a paradigm shift to painless, continuous, zero-finger pricking measurement in blood glucose monitoring. Recent electrochemical CGM sensors have reached two-week lifespans and no calibration with clinically acceptable accuracy. The system with the recent CGM sensors is identified as an “integrated glucose monitoring system,” which can replace finger-pricking glucose-testing for diabetes treatment decisions. Although such innovation has brought CGM technology closer to realizing the artificial pancreas, discomfort and infection problems have arisen from short lifespans and open wounds. A fully implantable sensor with a longer-term lifespan (90 days) is considered as an alternative CGM sensor with high comfort and low running cost. However, it still has barriers, including surgery for applying and replacing and frequent calibration. If technical refinement is conducted (e.g., stability and reproducibility of sensor fabrication), fully implantable, long-term CGM sensors can open the new era of continuous glucose monitoring.

We propose a simple, fast, height-scalable, and direct way to fabricate highly biocompatible polyethylene glycol diacrylate (PEGDA) microneedles. A needle-shaped distribution of ultraviolet (UV) exposure dose is formed in PEGDA by applying UV light through a rotating prism. A prism makes UV light rays bend, such that the base angle of the prism determines the inclined angle of the light. Thus, the microneedle height can be controlled by varying the base angles of the prism. We experimentally demonstrate the direct height-scalable potential. The microneedle height decreases and the microneedle tip angle increases with increases in the base angle of the prism. These results indicate that the microneedle geometry can be easily controlled by the base angle of a prism without additional microfabrication. In addition, unlike photoresist microneedles, PEGDA does not require any thermal baking, thus enabling well-defined symmetric needle formation with short process time. Therefore, the present method can facilitate PEGDA microneedles to practical applications. [2017-0136]

[Purpose] The purpose of this research was to examine differences in muscle activity between the resting forearm position (RFP) and the straight forearm position (SFP) during upper arm strengthening exercises. [Participants and Methods] In total, 35 healthy college students were randomly sampled (18 males and 17 females). Surface electromyography data were collected from the medial and lateral sides of the biceps and triceps brachii muscles. [Results] The medial muscles showed greater activity during SFP versus RFP, but no difference in overall activation was found between the two positions. [Conclusion] Carrying angle less affected to biceps and triceps brachii muscles activation during upper arm strengthening exercises.

A stretchable cell culture platform in which elastic micropneumatic actuators are embedded has been developed. By using the softlithography of polydimethylsiloxane (PDMS), the platform can be fabricated to any size and shape. It also permits cell culture by using the same standard methods that one would use with a Petri dish and it is transparent, permitting optical inspection of the cells. Thus, the platform is promising for studying cell responses because of mechanical stimulus. In this reported work, cells were cultured on a PDMS diaphragm of the micropneumatic actuators. Owing to input pressure, the micropneumatic actuators swell like a balloon, thereby stretching the cell membranes on the PDMS. The design flexibility of the presented approach is demonstrated by developing two kinds of stretchable platforms with diaphragm diameters of 558 and 24.8 μm to stretch whole and local cell membranes, respectively. Then, the cell membranes attached on the PDMS diaphragms are stretched by applying pressure on the pneumatic actuators. The applied stress causes an increase in the intracellular calcium ion concentration that is a fast cellular mechanotransduction. Therefore, it is concluded that the method for stretching cell membranes can stimulate either whole or local cell membranes, thus showing the potential to be used in in vitro studies of cellular mechanotransduction.

This paper describes a theoretical estimation of the geometry of negative epoxy-resist microneedles prepared via inclined/rotated ultraviolet (UV) lithography based on spatially controlled UV exposure doses. In comparison with other methods based on UV lithography, the present method can create microneedle structures with high scalability. When negative photoresist is exposed to inclined/rotated UV through circular mask patterns, a three-dimensional, needle-shaped distribution of the exposure dose forms in the irradiated region. Controlling the inclination angles and the exposure dose modifies the photo-polymerized portion of the photoresist, thus allowing the variation of the heights and contours of microneedles formed by using the same mask patterns. In an experimental study, the dimensions of the fabricated needles agreed well with the theoretical predictions for varying inclination angles and exposure doses. These results demonstrate that our theoretical approach can provide a simple route for fabricating microneedles with on-demand geometry. The fabricated microneedles can be used as solid microneedles or as a mold master for dissolving microneedles, thus simplifying the microneedle fabrication process. We envision that this method can improve fabrication accuracy and reduce fabrication cost and time, thereby facilitating the practical applications of microneedle-based drug delivery technology.

Diabetes can strike at any age, from childhood to adulthood, and lasts a lifetime. Thus, it is important to find ways to increase the quality of life for diabetic patients through intensive, continuous care of blood glucose concentrations. Glucose biosensors that are implanted under the skin are promising for continuous glucose monitoring because they can constantly read blood glucose concentrations and signal a warning in case of hypo- or hyperglycemia. The demand for subcutaneous glucose biosensors has led to the development of many glucose-sensing principles and sensor designs. This Review covers the effort to develop subcutaneous glucose biosensors, including the glucose-sensing principles, and discusses their current status for in vivo monitoring. In addition, the Review examines the future prospects for intensive diabetes care.

Polyacrylamide (PAM) hydrogels are widely used in bioanalysis and biosensing applications. Scaling down of PAM patterns to micro/nanosize extends PAM applications to lab-on-a-chip, highly sensitive biosensors and cell/tissue analysis. Proposed is a replica moulding technique to pattern the PAM surface down to nanosize. Various patterns on silicon moulds successfully transferred to PAM with a minimum dimension of 60 nm and aspect ratio of up to ∼9. PAM is characterised as a platform for a single cell array and the analysis of cell responses to topographic cues. Moreover, micro/nanopatterned PAM samples were implanted under the back skin of rats to study the topological effects on immuno responses in vivo. Therefore the use of micro/nanoreplica moulding to pattern PAM hydrogel provides opportunities for studying the relationship between soft nanoscaled structures and cell/tissue.

This paper presents active micromechanical motion amplifiers, inspired from the amplification principle of outer hair cells in cochlea, achieving the displacement amplification using the mechanical resonance modulated by variable stiffness springs. The proposed active micromechanical motion amplifiers modulate the resonant carrier motion using the variable stiffness springs whose stiffness changes depending on the input motion. We have designed, fabricated, and characterized two types of the amplifiers A and B, each having the variable stiffness spring designed to obtain different displacement gains. In the experimental study, we characterized the ratio of output stiffness change to input motion as 1.82 N/m/μm and 0.636 N/m/μm for the variable stiffness springs A and B, respectively. The displacement gains of the amplifiers A and B were measured as different values of 5.62 and 2.62, respectively. Therefore, we experimentally verified that the displacement gain of the proposed active micromechanical motion amplifier can be adjusted by the variable stiffness spring design. The present micromechanical motion amplifiers are capable to amplify the displacement based on the active amplification mechanism, thus having the potential to be used in high-sensitivity microsensors.

This paper presents a simple, low-cost, long-lasting UV-LED-based light source with uniform light intensity using a checkerboard half-mirror positioned within inverse L-shaped UV-LED arrays. The light rays from the top UV-LED array passed through the transparent portions of the checkerboard half-mirror, while the light rays from the side UV-LED array were reflected on the remaining opaque portions at right angles. Thus, uniform light intensity was achieved on the bottom area. Using the developed UV-LED light source, we fabricated microstructures with uniform shapes on a large area, thereby showing feasible applications for MEMS fabrication.

We present a micromechanical active amplifier, inspired from the principle of the outer hair cells in cochlea, amplifying both displacement and force. The present micromechanical active amplifier modulates the resonant carrier motion using the variable stiffness spring whose stiffness changes proportionally to the input motion. We design, fabricate, and characterize two types of the amplifiers A and B, each having the variable stiffness spring fur the maximum displacement gain and force gain, respectively. In the experimental study, the amplifier A shows the displacement gain of 5.62, which is 2.15 times larger than that of the amplifier 3. The amplifier B shows the force gain of 10.0, resulting in 1.26 times larger value compared to that of the amplifier A. We experimentally verify that the haircell-inspired micromechanical amplifiers are capable to amplify both displacement and force.

This research purposed to analyse the diversity of the long-term care system based on the dependency/independency of the aged. For this purpose, we divided the long-term care systems to three components; form of benefit, generosity of benefit and delivery system. Form of benefit is whether the benefit is cash or in-kind, and the generosity of benefit is related to the level and coverage of benefit. The last concerned to focus on provider and user selection. According to this, we tried to make an ideal type of long-term care in the perspective of citizenship and consumerism. As a result, we established four types of long-term care system; active citizen type, passive citizen type, latent citizen type, and family dependent type. And we investigated Austria, Sweden, Germany and Korea for each type empirically.

Arterial pulsation is deeply related to the diseases and physical properties of arteries. Cultivation of an artificial artery under various pulsation will reveal the interaction between pulsation and arterial stiffness. The ideal system can culture an artificial artery with pulsation and measure arterial stiffness, simultaneously. To reach the ideal system, we first developed the arterial pulsation simulator that could generate a periodic solitary-wave. The system is composed of three parts: a pulsation input part, a silicone tube, and a resistance part correspond to the human heart, the artery, the peripheral resistance, respectively. Previously, we could create a periodic solitary-wave by installing solenoid valve in the input part of the system. Although we could obtain pulsation-like wave-profiles, there was pressure drop after a period of pulsation; such pressure drop is not shown in in vivo pulsation. Since the pressure drop is originated from a reflection wave, fluidic resistance has to be controlled to realize in-vivo-like pulsation. However, effects of fluidic resistance on pulsation profiles has yet to be studied. We here present a fluidic-resistance control approach to minimize reflection waves. In experimental studies, we measured pulsation with two different fluidic resistances: one silicone tube with inner diameter of 4 mm and a silicone tubing network. In the silicone tubing network, one silicone tube with inner diameter of 4 mm branched to 16 silicone tubes with inner diameter of 2.5 mm. When fluidic resistance decreased 0.6 times, pressure drop in pulsation profiles decreased 0.6 times. Therefore, our approach can reduce reflective waves, thus having potential for pulsation control. Provided that further technical improvement (e.g., differential pressure measurement between fluidic resistances) is carried out, we envision that the fluidic-resistance control approach can provide a new route to reach in-vivo-like pulsation.

This paper describes a theoretical approach to give an irradiated area a uniform distribution of LED light intensity by synchronizing the signal waveforms and position control of the LEDs. Although UV-LEDs have attracted considerable attention as alternative light sources for ultraviolet (UV) lithography in Micro Electro Mechanical Systems (MEMS) fabrication, mainly because of their low cost and low power consumption, the realization of a uniform UV intensity over an area remains challenging. Here, we propose a method to achieve a uniform areal intensity within an irradiated area by synchronizing the signal waveform and position of a UV-LED array. To verify our theoretical calculation, we developed a system with a UV-LED array whose position is controlled by a linear actuator. The intensity of the UV-LED array is controlled by a pulse width modulation (PWM) signal, which is synchronized with the position of the linear actuator. Using this system, we fabricated 2D micropatterns and 3D microstructures with ...

This paper describes preliminary results of a method to regulate the shapes of a single bacterial cell by confining the cell into a micro chamber. The cell wall of Escherichia coli determines the rod-shape (0.5 μm in width, 2 μm in length) of the bacteria and protects from outer stress. We removed its cell wall by enzyme treatment and confined the cell into cross-shaped microchambers formed on the surface of 2% agar contained the growth media. We believe that our method could contribute to the comprehensive understanding of the shape regulation mechanism of E. coli. This paper focuses on the fabrication of cross-shaped microchambers formed on agar and confinement of the bacteria into the microchambers.

This paper describes a tunable lenticular lens to switch high-resolution two-dimensional (2D) / three-dimensional (3D) images in naked-eye stereoscopic displays. This lens is simply composed of transparent poly(dimethylsiloxane) (PDMS) microchannels and pumps to realizes two states: (A) flat surface for light transmissions without deflection; (B) cylindrically deformed surface for light deflection. This lens has three advantages: (i) switchable optical characteristics without patterned electrode, (ii) adjustable focal length by the pressure-driven deformation, (iii) simple fabrication and low-cost experimental setup. By using this device put on a Smart Phone display, we successfully observed 3D images and two different images depending on view angle. Moreover, we obtained clear 2D images without decrease in the horizontal resolution. We believe that this device can be applied to a portable and high luminance naked-eye stereoscopic display by the combination with various types of commercially available portable displays.

We present a portable glucose monitoring system comprised of an implantable fluorescent-hydrogel sensor, wearable photo detector, microcontroller, wireless device and software for transdermal, continuous glucose monitoring. Although we showed the potential of the fluorescent-hydrogel fibers for applying to long-term, implanted glucose monitoring, “true” continuous glucose monitoring with a portable monitoring system has yet to be realized. In the system that we propose here, the calculated glucose values show a good correlation with the actual blood glucose concentrations. The portable device attached to the ear of a rat and measured the fluorescence intensity for three days. Therefore, our system shows the potential for practical, “true,” continuous glucose monitoring.

Microenvironmental biophysical stimuli influence diverse cellular functions, such as directional motility and stem cell differentiation. Previously, researchers have tuned the linear stiffness of microposts to investigate cell mechanobiological processes and direct cellular behavior; however, microposts suffer from an inherent, yet critical drawback - regulation of micropost stiffness is fundamentally limited to “biaxial” control. To overcome this issue, here we utilize three-dimensional (3D) direct-write laser lithography processes to fabricate arrays of microscale springs (μSprings). By adjusting the geometric characteristics of individual μSprings, the x-, y-, and z-axis stiffness of the cellular substrate can be customized at the microscale. COMSOL simulations were performed to characterize the theoretical “triaxial” stiffness associated with a variety of μSpring designs. Endothelial cells seeded on μSpring arrays were found to successfully deform the μSprings via cell-generated forces. By enabling user-control over the triaxial stiffness of discrete, microscale substrate features, the presented μSpring methodology could offer a powerful platform for cellular studies and applications in fields including tissue engineering, biomaterials, and regenerative medicine.

We present a simple, fast nanochannel fabrication technique to develop hundred nanometer sized channels based on two-photon direct laser writing. By controlling laser power and location of a focused beam, we fabricated nanolines having minimum width of 180 nm. We also obtained nanochannels in the area of 110 μm × 25 μm by laser-writing with process time of 1 hour and verified rhodamine solution flowed into the nanochannels of 400 nm in width. Furthermore, this process can add desired nanochannels inside of pre-existing microfluidic systems. Therefore, we envision that the proposed nanochannel fabrication technique will facilitate technologies to detect DNA, proteins and chemicals in microfluidic systems.

This paper describes a simple and rapid process for the fabrication of 3D solid microstructures. We combined a conventional two-photon direct laser writing with a Parylene coating process. Two-photon direct laser writing allows us to make arbitrary 3D nano / micro structures, but it takes a long time to draw a 3D solid structure because the laser scans inside of photo-sensitive materials. Here, we deposited Parylene on the wire frame structure to fill the gap between the wires. This process allows us to rapidly form a solid surface on the wire frame structures. Our method can fabricate a cube of 100 μm × 100 μm × 40 μm 20 times faster compared to the conventional two-photon direct laser writing.

The use of fluorescence-based sensors holds great promise for continuous glucose monitoring (CGM) in vivo, allowing wireless transdermal transmission and long-lasting functionality in vivo. The ability to monitor glucose concentrations in vivo over the long term enables the sensors to be implanted and replaced less often, thereby bringing CGM closer to practical implementation. However, the full potential of long-term in vivo glucose monitoring has yet to be realized because current fluorescence-based sensors cannot remain at an implantation site and respond to blood glucose concentrations over an extended period. Here, we present a long-term in vivo glucose monitoring method using glucose-responsive fluorescent hydrogel fibers. We fabricated glucose-responsive fluorescent hydrogels in a fibrous structure because this structure enables the sensors to remain at the implantation site for a long period. Moreover, these fibers allow easy control of the amount of fluorescent sensors implanted, simply by cutting the fibers to the desired length, and facilitate sensor removal from the implantation site after use. We found that the polyethylene glycol (PEG)-bonded polyacrylamide (PAM) hydrogel fibers reduced inflammation compared with PAM hydrogel fibers, transdermally glowed, and continuously responded to blood glucose concentration changes for up to 140 days, showing their potential application for long-term in vivo continuous glucose monitoring.

Fluorescence-based implantable glucose sensors can provide continuous glucose monitoring (CGM) with wireless transdermal transmission and long-lasting activity in vivo. Here, we present a long-term in vivo glucose monitoring method using glucose-responsive fluorescent hydrogel fibers. The fiber structure enables the sensor to remain at an implantation site for a long period and be removed from the implantation site after use. We found that the polyethylene glycol (PEG)-bonded polyacrylamide (PAAm) hydrogel fibers reduced inflammation, transdermally glowed and continuously responded to blood glucose concentration changes after 2.5 months, showing their potential application for long-term in vivo continuous glucose monitoring.