Indicator Sensor Development and Fuel Cell Degradation Imaging

Although extensive research has been conducted, understanding the exact phenomena occurring during the operation of polymer electrolyte fuel cells (PEFCs) remains difficult. This research attempted to identify new reasons for the reduced performance of PEFC using an imaging technique. To begin with, H⁺ and OH⁻ indicator sensors, which display red, blue, and green values (RGB) using digital microscopes, are developed and attached to each electrode of a membrane electrode assembly to enable quantitative analysis of ion generation. The proposed reaction in the fuel cell can be confirmed, and various reactions occurring in the electrode can be examined using this approach. In particular, H⁺ is generated at the anode and cathode of the anion exchange membrane fuel cell, which is found to be a major cause of performance deterioration.     

一种利用磁场探测来计算车流量的方法

车辆是长期处于地磁场环境下被磁化而带有磁性的铁磁性物质较多的物体，它们即使经过消磁处理，但本身还有一定的剩磁。磁阻传感器具有很高的分辨率。当汽车通过传感器时，传感器会纪录下磁场的变化量。设计了一套电路来实现车辆磁场的探测，进而可以进行车流量统计，具有一定的实用性。     

Self‐Powered Trajectory,Velocity, and Acceleration Tracking of a Moving Object/Body using a Triboelectric Sensor

Motion tracking is of great importance in a wide range of fields such as automation, robotics, security, sports and entertainment. Here, a self‐powered, single‐electrode‐based triboelectric sensor (TES) is reported to accurately detect the movement of a moving object/body in two dimensions. Based on the coupling of triboelectric effect and electrostatic induction, the movement of an object on the top surface of a polytetrafluoroethylene (PTFE) layer induces changes in the electrical potential of the patterned aluminum electrodes underneath. From the measurements of the output performance (open‐circuit voltage and short‐circuit current), the motion information about the object, such as trajectory, velocity, and acceleration is derived in conformity with the preset values. Moreover, the TES can detect motions of more than one objects moving at the same time. In addition, applications of the TES are demonstrated by using LED illuminations as real‐time indicators to visualize the movement of a sliding object and the walking steps of a person.     

基于复合光波导偏振干涉技术的高灵敏度生化检测仪

利用射频溅射技术在一个单模玻璃光波导的局部表面淀积一层两端呈梯度的高折射率透明氧化物薄膜,形成低损失、高灵敏度平面复合光波导芯片。这种结构能够使得玻璃光波导内沿同一路径传播的横电基模(TE0)与横磁基模(TM0)在梯度薄膜区间产生纵向空间分离,导致TE0模的消逝场相比TM0模显著增强。利用复合光波导芯片,结合棱镜-样品池组合体和集成式选偏光探测器研制出基于偏振干涉测量的OWG-01型生化检测仪。对液体折射率响应的测试结果表明复合光波导芯片的热光效应非常小,而仪器的测量误差主要来自待测液体自身的折射率随温度的变化。     

颜色探测的研究与进展

介绍了基于光吸收系数强烈依赖于波长的硅色敏器件的结构、颜色探测的信号处理电路以及颜色探测应用的研究与进展。利用双结色敏器件和合适的信号处理电路,已使单色光的分辨能力达到了纳米量级．     

阵列通道复增益盲估计

在阵列接收机各通道增益和相位不一致时,基于模型的超分辨波达方向估计性能大大下降。在已知２个信号的波达方向差的条件下,提出一种基于四阶累量进行盲信号处理的新算法。在方法中首先求出阵列流形,然后利用搜索法估计阵列通道复增益矩阵。     

高精度PWM输出的温度传感器MAX6666/6667的特性及应用

介绍了MAXIM公司研制的新型高精度PWM输出温度传感器MAX6666/6667的主要性能及其典型应用电路。     

Design of Engineered Elastomeric Substrate for Stretchable Active Devices and Sensors

In the field of flexible electronics, emerging applications require biocompatible and unobtrusive devices, which can withstand different modes of mechanical deformation and achieve low complexity in the fabrication process. Here, the fabrication of a mesa‐shaped elastomeric substrate, supporting thin‐film transistors (TFTs) and logic circuits (inverters), is reported. High‐relief structures are designed to minimize the strain experienced by the electronics, which are fabricated directly on the pillars' surface. In this design configuration, devices based on amorphous indium‐gallium‐zinc‐oxide can withstand different modes of deformation. Bending, stretching, and twisting experiments up to 6 mm radius, 20% uniaxial strain, and 180° global twisting, respectively, are performed to show stable electrical performance of the TFTs. Similarly, a fully integrated digital inverter is tested while stretched up to 20% elongation. As a proof of the versatility of mesa‐shaped geometry, a biocompatible and stretchable sensor for temperature mapping is also realized. Using pectin, which is a temperature‐sensitive material present in plant cells, the response of the sensor shows current modulation from 13 to 28 °C and functionality up to 15% strain. These results demonstrate the performance of highly flexible electronics for a broad variety of applications, including smart skin and health monitoring.     

Hierarchically Structured Self‐Healing Sensors with Tunable Positive/Negative Piezoresistivity

It is a challenge to manufacture flexible sensors that possess easily distinguishable biomotion signals, strong response reliability, and excellent self‐healing capability. Herein, a self‐healing sensor with tunable positive/negative piezoresistivity is designed by the construction of hierarchical structure connected through supramolecular metal–ligand coordination bonds. The developed sensors can be integrated with the human body to detect multiple tiny signals, such as pronunciation, coughing, and deep breathing. Interestingly, the nanostructured elastomer sensor with and without a flexible yarn electrode shows negative and positive current signals, respectively, making it easy to be identify. Furthermore, it exhibits very fast (2 min), autonomous, and repeatable self‐healing ability with high‐healing efficiency (88.6% after the third healing process). The healed samples still possess flexibility, high sensitivity, and accurate detection capability, even after bending over 10 000 cycles. The excellent biomimetic self‐healing performance combined with the tunable piezoresistivity make it promising for next‐generation wearable electronics.     

An Integrated CMOS Front-End for Optical Absolute Rotary Encoders

This paper presents a front-end circuit for optical rotary encoders. The light pulses modulated by the encoder disc are transduced into current signals, which are pre-processed and converted into digital waveforms related to the disc angular position information. The proposed front-end circuit is compensated against temperature drifts. Digitally programmable calibration is provided to account for spreads in impinging light pulse power. Measurement results on integrated prototypes are shown, demonstrating correct operation of the front-end with an optical input power from 0.5 W to 3 W up to a signal frequency of 500 kHz in a temperature range from 0 °C to 80 °C.