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An enzymatic glucose sensor was fabricated and integrated into a heterodyne refractometer. A heterodyne light source was incident into the sensor which the circular birefringence refractive index of sample was changed as the chemical reaction between glucose oxidase and glucose progressed. Therefore, the phase difference before and after chemical reaction could be measured by a lock-in amplifier with phase-lock technology. The optical configuration and measurement procedures indicated that the alignment of the measurement system was straightforward and that it reduced the misalignment effect. The phase stability of the proposed system was superior to 0.04 deg within 1 min. The glucose sensor can be reused 100 times while retaining favorable performance. The results indicated that the resolutions of the proposed method were ∼1.5 and 1.29 mg / dl for the glucose solution and serum-based sample (SRM 965b), respectively. The calibration curve revealed high linearity within the dynamic range of 0 to 300 mg / dl. Based on these findings, the proposed method has a potential to measure the whole blood glucose concentration for daily monitoring.

This study proposed a designing method for lampshade with free-from surface and fabricated the optimum lampshade structure with 3D printer. Theoretical and measurement results showed high similarity and preserved lower power consumption.

A design method and corresponding fabrication procedures are proposed for a dual frusto-conical reflector of a downlight luminaire. The profile of the dual frusto-conical reflector consists of two flat-slant reflective surfaces with slightly different slopes. The optimum dual frusto-conical reflector can be obtained with the proposed design method. The finished product of the dual frusto-conical reflector is fabricated by a 3D printer and followed by surface polishing and reflection paint spraying. The measurement results show that luminaires exhibited 70% optimum illuminance confined within an illumination area of 1.8 m 2 , and the optimum illumination intensity is at 252 lux. The optimum efficiency of the proposed luminaire can reach 158 lm/W for normal-white light-emitting diode (LED) and 119 lm/W for warm-white LED, respectively.

An antireflection (AR) coating is fabricated by applying an optimal spin-coating method and a pH-modified SiO2 nanoparticle solution on a cover glass. Because the pH value of the solution will affect the aggregation and dispersion of the SiO2 particles, the transmittance of the AR-treated cover glass will be enhanced under optimal fabricated conditions. The experimental results show that an AR coating fabricated by an SiO2 nanoparticle solution of pH 11 enhances the transmittance approximately by 3% and 5% under normal and oblique incident conditions, respectively. Furthermore, the AR-treated cover glass exhibits hydrophobicity and shows a 65% enhancement at a contact angle to bare glass.

Manufacturing and testing of a TMG (thermoelectric microgenerator) with CNCs (carbon nanocapsules) film fabricated utilizing a CMOS (complementary metal oxide semiconductor) technology are investigated. The microgenerator includes a CNCs layer, thermopiles, and thermometers. CNCs, a heat absorbing material, are coated on the microgenerator, so that the TD (temperature difference) of HP (hot part) and CP (cold part) in the thermopiles increases, resulting in an enhancement of the microgenerator OP (output power). Thermometers fabricated in the microgenerator are employed to detect the HP and CP temperature in thermopiles. In order to enhance thermopiles&rsquo, TD, the HP in thermopiles was manufactured as suspension structures isolating heat dissipation, and the CP in thermopiles was made on a silicon substrate to increase the heat sink. Experiments showed that the microgenerator OV (output voltage) was 3.3 mV and its output power was 125 pW at TD 3 K. Voltage and power factors of TMG were 0.71 mV/K/mm2 and 9.04 pW/K2/mm2, respectively.

This paper demonstrates the antireflection coating of SiO 2 nanospheres applied to cover glass by using the optimal spin-coating method. Because of the hydrolysis and condensation reactions between the SiO 2 nanosphere antireflection (AR) coating and n-octadecyltriethoxysilane solution (C 18 -TEOS), the contact angle of the AR coating with hydrophobic treatment is improved approximately 38%, and the moisture-resistance remains unchanged, which preserved similar transmittance for six weeks. Furthermore, the AR coating with hydrophobic treatment exhibits approximately 3% and 7% improvement in the transmittance at normal and oblique incidence, respectively. The hydrophobic and omnidirectional AR coating with nanoscale SiO 2 particles can be fabricated using the proposed simple and economical method.

This study proposes a Littrow-type self-aligned laser encoder system (LisaLENS) with double diffractions. The LisaLENS has simple optical paths, facilitating alignment and manufacture, and fewer optical components than current laser encoders. This study analyzes the theoretical measurement resolution of this system and verifies the feasibilities of its long- and short-range measurements through experiments. Experimental results show that the LisaLENS has a resolution of 5.5±1.4 nm. Thus, this design has wide applications in various fields, especially for monitoring the displacement and vibration of precision-motorized stages.

This paper proposes a novel common-path laser encoder with a Littrow configuration (CPLi). The CPLi combines the merits of the 1 − x telescope and Littrow mount so that the CPLi can have high tolerance to head-to-scale runout. The CPLi can effectively slash the environmental disturbance effect to its lowest level. The runout tolerance is found to be 1.5–3 times greater than that of our previous work. The experimental results of the CPLi match well with those of the HP5529A for long-range measurements. The CPLi attains a measurement resolution of 0.12 ± 0.021 nm. Its system stability is as low as −0.25 ± 0.098 nm/h. It has a promising potential for nanometer resolution and long-range applications.

This paper presents the fabrication and characterization of energy harvesting thermoelectric micro generators using the commercial complementary metal oxide semiconductor (CMOS) process. The micro generator consists of 33 thermocouples in series. Thermocouple materials are p-type and n-type polysilicon since they have a large Seebeck coefficient difference. The output power of the micro generator depends on the temperature difference in the hot and cold parts of the thermocouples. In order to increase this temperature difference, the hot part of the thermocouples is suspended to reduce heat-sinking. The micro generator needs a post-CMOS process to release the suspended structures of hot part, which the post-process includes an anisotropic dry etching to etch the sacrificial oxide layer and an isotropic dry etching to remove the silicon substrate. Experiments show that the output power of the micro generator is 9.4 mW at a temperature difference of 15 K.

This study proposes a novel common-path laser encoder (CPLE) capable of effectively minimizing environmental disturbance. The proposed CPLE uses a two-aperture phase-shifting technique to form quadrature signals. Experimental results match well with HP5529A results for long-range measurements. Results also show that the estimated measurement resolution is 0.1 ± 0.046 nm. Therefore, the proposed design has great potential for nanometer resolution and long-range applications.

In this study, we fabricated a wireless micro FET (field effect transistor) pressure sensor based on the commercial CMOS (complementary metal oxide semiconductor) process and a post-process. The wireless micro pressure sensor is composed of a FET pressure sensor, an oscillator, an amplifier and an antenna. The oscillator is adopted to generate an ac signal, and the amplifier is used to amplify the sensing signal of the pressure sensor. The antenna is utilized to transmit the output voltage of the pressure sensor to a receiver. The pressure sensor is constructed by 16 sensing cells in parallel. Each sensing cell contains an MOS (metal oxide semiconductor) and a suspended membrane, which the gate of the MOS is the suspended membrane. The post-process employs etchants to etch the sacrificial layers in the pressure sensor for releasing the suspended membranes, and a LPCVD (low pressure chemical vapor deposition) parylene is adopted to seal the etch holes in the pressure. Experimental results show that the pressure sensor has a sensitivity of 0.08 mV/kPa in the pressure range of 0–500 kPa and a wireless transmission distance of 10 cm.

In this study we used the commercial 0.35 µm CMOS (complementary metal oxide semiconductor) process and simple maskless post-processing to fabricate an array of micromirrors exhibiting high natural frequency. The micromirrors were manufactured from aluminum; the sacrificial layer was silicon dioxide. Because we fabricated the micromirror arrays using the standard CMOS process, they have the potential to be integrated with circuitry on a chip. For post-processing we used an etchant to remove the sacrificial layer and thereby suspend the micromirrors. The micromirror array contained a circular membrane and four fixed beams set symmetrically around and below the circular mirror; these four fan-shaped electrodes controlled the tilting of the micromirror. A MEMS (microelectromechanical system) motion analysis system and a confocal 3D-surface topography were used to characterize the properties and configuration of the micromirror array. Each micromirror could be rotated in four independent directions. Experimentally, we found that the micromirror had a tilting angle of about 2.55° when applying a driving voltage of 40 V. The natural frequency of the micromirrors was 59.1 kHz.

The precision positioning device becomes significant requirement in scientific instruments used for the applications of nanotechnology for a few decades. To achieve the high resolution positioning, the sensing methods of displacement sensor become more important in positioning device. In this paper, a novel method is presented for measuring both in-plane/out-plane displacements with the single heterodyne grating interferometry (HGI). We demonstrated the 1D, 2D, and 3D measurement results respectively and the smallest displacement can be detected was better than 6 pm. Furthermore, the nanometer resolution can be ensured within 20 µm displacement. Hence, the in-plane/out-plane measurements with single apparatus can be realized by our method and might be a displacement sensor using in the motorized stage with suitable opto-mechanics structure minimization.

A novel method is presented for one-dimensional (1-D) and two-dimensional (2-D) in-plane displacements measurement that is based on the heterodyne grating interferometry. The novel setup of the optical configuration reduces the airstreams disturbance and maintains the environmental vibration at minimum level, allowing high stability and low measurement error to be achieved. Resulting from the theoretical calculation, our method can be sensitive to the sub-picometer level. With highly controlled isolation system, the low frequency noise can be reduced to minimum level, and only high frequency noises are considered, our method can achieve the resolution about 0.5 nm within 250 μm displacement. In addition, 2-D in-plane displacement measurement can be accomplished with a single interferometer simultaneously.

A novel method for displacement measurement is presented. The measurement system includes a heterodyne light source, a moving grating and a lock-in amplifier for phase measurement. The optical phase variation, which stems from the grating movement, is measured by an optical heterodyne interferometer. The experimental results demonstrate that our system can measure small and long displacement with subnanometric resolution. The theoretical resolution is about 1 pm. By means of isolating the measurement system, the low frequency noise can be reduced, and when only high frequency noises are considered, our method can achieve measurement resolution of about 0.2 nm.

The fabrication of a nanowire WO3 humidity sensor integrated with an inverting amplifier circuit and a micro-heater on a chip using the commercial 0.35 μm complementary metal oxide semiconductor (CMOS) process and a post-process have been implemented. The humidity sensor is composed of a sensing resistor and a humidity sensing film. Tungsten trioxide prepared by a sol–gel method is adopted as the humidity sensing film. The fabrication of the humidity sensor requires a post-process to etch the sacrificial layers and to expose the sensing resistor, and then the humidity sensing film is coated over the sensing resistor. The humidity sensor, which is a resistive type, changes the resistance when the sensing film adsorbs or desorbs water vapor. An inverting amplifier circuit is utilized to convert the resistance of the humidity sensor into the voltage output. The micro-heater is utilized to provide a super-ambient working temperature to the humidity sensor, which can avoid the humidity sensor to generate the signal drift. Experimental results show that the sensitivity of the humidity sensor is about 4.5 mV/% RH at 60 °C.

We demonstrate a glucose fiber sensor for measuring glucose concentration in serum. High resolution and rapid measurement are achieved through the integration of highly selective enzymes and heterodyne interferometry. The best resolution and response time obtained are 0.14 mg/dL and 1.3 s, respectively. The stability of the sensor is also verified by investigating the initial phase variation. Experimental results show that the fiber sensor can be reused more than 10 times.

This paper is concerned with the design of a laser linear encoder with high head‐to‐scale alignment tolerance. It adopts 1-x telescope design that can increase by 6 to 20 times the head‐to‐scale tolerance of existing encoders of the same class. The optical design of the laser encoder can avoid effects from differences in polarization diffraction efficiencies. In other designs the non‐uniformity of the temperature field within the head‐to‐scale range yields a nonzero initial phase and thus decreases the measurement accuracy of the system. The misalignment of the polarizers for the circular polarization interferometer configuration makes for both inclined and elliptical quadrature signals in the output. For an encoder system which adopts an arctangent algorithm, this effect may lower the measuring resolution. The resolution of our laser encoder design is verified by experiments.

In this study, we proposed a in-plane displacement measurement which consisted of reflection type displacement sensor and heterodyne interferometer. The displacement sensor is fabricated by volume hologram which recorded the interference signal and became the reflection type diffracted grating. Based on the optical configuration of the heterodyne interferometer, the diffraction beams will interfere and possess the information of the displacement of the sensor. To analysis the heterodyne interference signal with lock-in technique, the in-plane displacement can be obtained simultaneously. According to our results, the sub-nanometer resolution can be accomplished.

In this paper a novel common-path laser encoder system for nanopositioning is proposed, that can effectively reduce the environmental disturbance at its lowest level. It has promising potential for nanometer resolution and large range applications. The experimental results of the proposed laser encoder match well with ones of HP5529A for large ranges. The tested results also show that it has the capability of nanometer scale measurement resolution.

Grating interferometers overcome the diffraction limit of optical waves. They can provide nano-scale displacement resolution, and will have great potential for nano-metrology applications. The optical configurations of used grating interferometers are Michelson's type with different paths between the measurement beam and reference beam. Environmental disturbance can directly enter the measured signals and cannot be essentially slashed. Thus the accuracy of the used grating interferometers becomes dramatically worse. In this paper, a homodyne common-path grating interferometer is proposed, that can reduce the environmental disturbance at its lowest level. It has promising potential for nanotechnology applications. The measurement principle and experimental verifications are done in the work.

A novel laser encoder is presented for sub-nanometer displacement measurement. It is based on optical heterodyne interferometry and two arms of compensation optics with a symmetric and quasi-common-path optical configuration in polarization space. High stability and resolution can be achieved for displacement measurements. The theoretical analysis shows that our method can effectively compensate misalignments resulting from the dynamic runout in laser encoders. Experimental results reveal that the laser encoder can measure a displacement in subnanometer scale and in millimeter travel range.

Laser encoders as an optical displacement measurement technique have many applications such as modern manufacturing, scanning probe microscopy (SPM) and nanomanipulation. For the measurement scale down to the nanometer range, the stability, sensitivity and tolerance to dynamic runout are the key issues for laser encoders. This paper presents a novel laser encoder for sub-nanometer displacement measurement. It is based on optical heterodyne interferometry and conjugate optics with a symmetric and quasi-common-path optical configuration. It offers high stability, high resolution, low uncertainty displacement measurements and can break through the dynamic runout problem in laser encoders. Experimental results reveal that the laser encoder can detect a displacement variation of 26 pm, and can thus be applied to sub-nanometer or even picometer positioning.

The thermal optical properties of a holographic material were measured using total internal reflection heterodyne interferometry. The effective thermal expansion coefficients (ETECs) of the holographic material were determined at various exposure times. Our results showed that the holographic material exhibited a smaller thermal expansion coefficient (TEC) with a longer exposure time than those materials with short exposure times. Thus the diffraction power increased as the exposure time of the holographic material increased. Furthermore, the proposed method provides a highly accurate means of measurement for determination of the TEC. The theoretical ETEC error of the proposed method is better than 1.1×10 −7 and the practical ETEC error under the precision measurement conditions can reach to 2.3×10− 6 .

A novel method of the measurement of in-plane displacement is presented. This method includes a heterodyne light source, a moving grating and a lock-in amplifier for phase measurement. The phase variation which resulted from the grating movement is measured by an optical heterodyne interferometer. The short and long displacement can be measured by our method. The theoretical resolution is about 1 pm. If considering the high frequency noise, the measurement error or resolution is about 0.2 nm yet.

Laser encoders overcome the fundamental resolution limit of geometrical optical encoders by cleverly converting the diffraction limit to phase coded information so as to facilitate nanometer displacement measurement. As positioning information was coded within the optical wavefront of laser encoders, interferometry principles thus must be adopted within the design of the laser encoders. This effect has posed a very strong alignment tolerance among various components of the whole laser encoder, which in turn impose a serious user adaptation bottleneck. Out of all alignment tolerance, the head-to-scale alignment tolerance represents the most important hindrance for wider applications. Improving the IBM laser optical encoder design by taking into the consideration of manufacturing tolerance of various optical components, an innovative linear laser encoder with very high head-to-scale tolerance is presented in this article. Efficiency of the TE/TM incident light beams on the grating scale used are examined theoretically and verified experimentally so as to provide design optimizations of the grating scale. Effect of various grating scale, quartz master or polymer-based grating replicate, is also detailed. Signal processing used to decoded the quadrature based positioning optical signal is also studied. Experimental results that verify the resolutions of the tabletop laser encoder prototype by comparing the decoded quadrature signal and a HP laser interferometer output signal is also presented.

This paper presents a heterodyne common-path grating interferometer with Littrow configuration (HCGIL). The HCGIL can effectively overcome environmental disturbance effect and the DC offset and the amplitude variation of the measurement signals. Experimental results match well with the HP5529A results for long-range measurements. Results also show that the estimated measurement resolution is 0.15 ± 0.027 nm. The stability of the HCGIL is -0.41 ± 0.23 nm. Therefore, the HCGIL has potential for subnanometer resolution and long-range applications.

This paper presents a novel laser encoder for sub-nanometer displacement measurement. It is based on optical heterodyne interferometry and two sets of conjugate optics with a symmetric and quasi-common-path optical configuration. It offers displacement measurements of high stability, high resolution. The theoretical analysis shows that our method can effectively compensate misalignments resulting from the dynamic runout in laser encoders. Experimental results reveal that the laser encoder can detect a displacement variation down to sub-nanometer range.

We introduce a new configuration for the optical head of a newly developed diffractive laser encoder system. This configuration has a high manufacturing tolerance and a high head-to-scale alignment tolerance, both of which can enhance the wider potential applicability of this newly designed laser encoder. The measurement principles of the encoder are discussed and detailed. We optimized the grating shape and analyzed the impact of the optical components and their arrangement on the measurement error. The head-to-scale alignment tolerance and the arrangement of components in the encoder were also determined. Finally, the measurement performance was evaluated and analyzed. Under nonenvironmentally controlled conditions, the measurement accuracy was found to be 37.3 nm with a standard deviation of 25.4 nm.