A biologically inspired compound eye system is fabricated for the detection of object motion without the need for sophisticated image processing. The array of the artificial optical unit, called ommatidium, structurally and functionally mimics the natural compound eyes for motion detection. Each artificial ommatidium consists of polymer lenses, a light-guiding polymer cone, a 3D printing cladding, and a light intensity sensor to measure the change of light intensity during motion detection. To simplify the signal processing and improve the system reliability, low-cost light sensors, instead of CMOS/CCD arrays, are used for measuring the light intensity changes caused by object movement. The distance and speed of a moving metal ball of a pendulum were measured using the compound eye system. The measured results agree well with the theoretical analyses. The error between the measured and calculated speed is less than 2%.

For the first time, this paper presents corrosion resistant and high-capacity implantable titanium nitride (TiN) nanotubes electrodes for the application of neural probes. Traditionally, the TiN electrodes are prepared using reactive sputtering techniques and have limited surface areas. To research smaller electrodes to minimize tissue damage, high aspect ratio TiN nanotube structures with high surface areas were fabricated using electrochemical anodization of Ti wires followed by high-temperature nitration. The specific charge capacity of nanoporous TiN was found proportionally with the surface area and pore size. Compared to tungsten electrode, the impedance and morphology of nanoporous TiN was found stable in an accelerated stress test (at an elevated temperature in phosphorous buffered solution).

Microelectrodes are widely used as a peripheral nerve interface (PNI) to connect the peripheral nerve to a computer for restoration of sensorimotor function and bionic device motion control. Materials used for implantable microelectrode are still facing the challenges from biocompatibility and bio‐fidelity in neural signal recording and nerve stimulating. In this study, we report that carbon multi‐electrode arrays (cMEAs) can be fabricated using carbon ink, micro resin dimethylsiloxane and 3D printing technology and ink for PNI. In vitro cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) demonstrated that the cMEAs have higher charge storage capacity (CSC) and less impedance than conventional platinum (Pt) electrode. In vivo studies using an animal model demonstrated that cMEAs are more effective in stimulating the nerve to elicit muscle contraction and recording compound muscle action potentials (CMAPs) than the Pt electrode. The cMEAs has lower stimulating threshold to elicit muscle activity, higher signal‐to‐noise (SNR) in CMAP. Our studies demonstrate that cMEAs can be an advanced healthcare materials in nerve signal nerve stimulation for PNI and muscle bioelectrical signal recording for peripheral muscle interface (PMI).

For the first time, this paper investigates anodic bonding using the latest chemically-strengthened glass called Gorilla Glass (from Corning). Gorilla Glass has many excellent properties for MEMS/NEMS applications, including hardness (resistance to scratching), flexibility, high fracture toughness and antibacterial resistance. However, the high thermal expansion coefficient of Gorilla Glass (7.58ppm/°C) makes it doubtful for anodic bonding, where high temperature (200∼4000C) and high electrical field are applied to facilitate silicon to glass bonding. We show that the presence of the potassium ions at the surfaces of Gloria Glass not only makes the glass more resistant to damage but also facilitates the process of anodic bonding (including lower bonding temperature and voltage). With the proper cooling conditions, it is also feasible to develop silicon-glass microstructures based on the principle of stress engineering.

For the first time, this paper presents micromachining of gorilla glass, which is a new tough and transparent substrate, but has not been used in MEMS yet. We have demonstrated that microstructures made of Gorilla glass have several advantages for MEMS applications, including flexibility and high fracture toughness. Wet etching with hydrofluoric acid (HF) was found more effective because it prevents creation of sharp corners. The process was optimized with an additive of hydrochloric acid (HCl) to reduce surface roughness, and the etching rate is approximately 12 μm/min. The microcantilevers made of Gorilla glass is capable to bend 12.26 degrees without breaking, which is very different from the conventional brittle glass (including Pyrex or Borosilicate).

该文研究了一种覆盖六氟-2-羟基异丙基聚硅氧烷（SXFA）敏感膜,并针对有机磷化学物检测的新型Love波传感器,采用36°YX-LiTaO3与SiO2分别作为Love波延迟线器件的压电基底与波导层材料。将所研制的Love波器件作为差分振荡器的频率控制单元,结合SXFA敏感膜,开展了针对甲基磷酸二甲（DMMP）的气体传感实验,分析了不同波导层膜厚对Love波传感器气体响应的影响,并与传统瑞利型声表面波模式的气体传感器性能进行了对比,实验结果显示,Love波模式传感器表现出高灵敏度特性。

The optimization of fluorinated bisphenol-containing polymer (BSP3)-coated surface acoustic wave (SAW) chemical sensor was performed for sensing organo phosphorous compounds with trace concentration in this contribution. First, the response mechanism was characterized using the classical perturbational approach. Optimal sensitive film thickness and operation frequency are determined theoretically to achieve a relative linear characteristic response and a high gas sensitivity. Next, to improve of the corrosion resistance and frequency response characteristics of the sensor chip, Al/Au electrodes are used to form the resonator acted as the feedback element for oscillator. In addition, the substantial improvement is obtained in frequency stability of the resonator-oscillator referring to phase modulation approach. The measured short-term frequency stability of the oscillator at the operation frequency of 300 MHz is up to 2 Hz/s. The theoretical predictions are confirmed by the measured responses from the BSP3-coated SAW sensor for dimethylmethylphosphonate (DMMP) detection. Excellent threshold detection limit less than 0.004 mg/m 3 and good sensitivity (~3.09 kHz/mg/m 3 ) were achieved from the developed BSP3-coated SAW chemical sensor in the DMMP detection.

A temperature-compensated Love wave device was proposed for gas sensing utilizing a waveguide structure of SiO2/36 degrees YX LiTaO3. Significant improvement in the temperature stability of the hybrid Love wave device was implemented by varying the guiding layer thickness. The optimal values yielding low cross-sensitivity to temperature and high mass sensitivity in gas sorption were determined theoretically by solving the coupled electromechanical field equation in layered media. The theoretical analysis was confirmed experimentally in dimethylmethylphosphonate (DMMP) detection by using a fluoroalcoholpolysiloxane (SXFA) coated Love wave sensor. The experimental results indicate that better sensitivity and excellent temperature stability were obtained from the developed Love wave gas sensor over the Rayleigh surface acoustic wave (R-SAW) sensors.

研究了基于ST-90°X石英基片和SU-8波导层的乐甫波器件的温度特性.采用电极宽度控制单向单相(EWC/SPUDT)结构和铝电极,设计制作了具有单一模式控制功能和低插入损耗的150 MHz剪切型声表面波(SH-SAW)延迟线器件,并在其表面涂覆不同膜厚的SU-8声波导层构成系列乐甫波器件.由于SU-8波导层与石英基片温度系数的相反极性特性,SU-8膜厚直接影响到了乐甫波器件的温度特性.实验发现,覆盖不同膜厚的SU-8的乐甫波器件的中心频率随温度呈非线性变化,且在60～80℃内,SU-8膜厚为0.95 μm时,其频率温度系数约为0.830×10-6/℃.

Temperature characteristics of SU-8 photoresist coated love wave devices are presented from 0 °C to 120 °C. Surface skimming bulk wave (SSBW) and love wave delay line devices were fabricated on the ST-90°X quartz substrate. Effects of SU-8 thickness on insertion loss and temperature range of near-zero temperature coefficient of frequency (TCF) are investigated. Love wave devices with -15.5dB to -22.4dB insertion loss and near zero TCF from 60 °C to 100°C are demonstrated in the 150MHz range.

Temperature characteristics of SiO2-coated Love Wave oscillators are presented from 10 °C to 60 °C. Surface skimming bulk wave (SSBW) and Love Wave delay line devices were fabricated on the 36 °YX-LiTaO3 substrate. Near zero TCF of SiO2-coated Love Wave oscillators from 10 °C to 60 °C are demonstrated in the 150MHz range. In the gas sensor experiment on dimethylmethylphosphonate (DMMP) detection, the fabricated SXFA-coated chemical sensor exhibited a threshold detection limit and high sensitivity.