•Inspired by biological cells, a kind of TENG energy-harvesting skin is developed.•The TENG can endure a strain of 600% and has a transmittance of as high as 62.5%.•The TENG can sustainably power an electronic watch with sorely human motion.•The TENG is combined with a micro supercapacitor by sharing the same solution.A bioinspired soft and stretchable triboelectric nanogenerator (TENG) is developed as energy-harvesting skin to drive personal electronics by scavenging biomechanical energy. Drawn inspiration from biological cells, the TENG consists of patterned interconnected cellular structures, with physiological saline as the electrode and silicone rubber as the encapsulation and triboelectric layer. The TENG can withstand a strain of 600% and has a transmittance of as high as 62.5%. The TENG can keep its high performance under various strain. The TENG also has the desirable features of biocompatibility, simple fabrication, light weight and environmental protection. The maximum instantaneous power density (2.3 Hz) and direct current power density of the TENG are ~ 11.6 W/m2 and ~ 2.65 mW/m2 respectively. Mounted on the skin, the TENG integrating with a power management unit can sustainably drive an electronic watch sorely by harvesting energy from hand motion. A stretchable self-charging power unit with a TENG and a micro supercapacitor sharing the same solution is created, with the solution as both the electrode of the TENG and the electrolyte of the supercapacitor. This work opens up new insights for clean power sources of skin-mounted electronics and promotes the development of sustainable energy supply for wearable and portable electronics.Download high-res image (234KB)Download full-size image

Surface acoustic wave (SAW) sensors and micro-electromechanical system (MEMS) technology provide a promising solution for measurement in harsh environments such as gas turbines. In this paper, a SAW resonator (size: 1107 μm× 721 μm) based on the AlN/4H-SiC multilayer structure is designed and simulated. A MEMS-compatible fabrication process is employed to fabricate the resonator. The results show that highly c-axis-oriented AlN thin films deposited on the 4H-SiC substrate are obtained, with that the diffraction peak of AlN is 36.10° and the lowest full width at half maximum (FWHM) value is only 1.19°. The test results of the network analyzer are consistent with the simulation curve, which is very encouraging and indicates that our work is a significant attempt to solve the measurement problems mainly including high temperature stability of sensitive structures and the heat transmission of leads in harsh environments. It is essential to get the best performance of SAW resonator, optimize and characterize the behaviors in high temperatures in future research.在高温等恶劣工作环境下, 燃气轮机有着迫切的温度等工况参数的实时监测需求。声表面波(SAW)技术与微机电系统(MEMS)技术的结合可提供一种很有发展前景的解决方案。本文旨在探讨SAW 谐振器的设计与仿真方法, 研究高质量c 轴择优取向的AlN 压电薄膜制备工艺及与MEMS 工艺兼容的SAW 谐振器制作工艺, 并测试其电学性能以验证SAW 谐振器设计与制作的正确性与可行性。1. 首次在耐高温材料AlN/4H-SiC 上设计、仿真及制作SAW 谐振器并测试电学性能; 2. 在4HSiC上得到了高质量c 轴择优取向的AlN 压电薄膜并开发了一套与MEMS 工艺兼容的SAW 谐振器制作工艺。1. 通过对SAW 谐振器所有结构参数的设计与仿真, 得到谐振器的谐振频率与反谐振频率等(图2 和3); 2. 利用磁控溅射方法在4H-SiC衬底上溅射高质量c 轴择优取向的AlN 压电薄膜, 再利用光刻、湿法腐蚀等MEMS 工艺制作SAW 谐振器(图4); 3. 通过扫描电镜和X 射线衍射等手段, 检测AlN 压电薄膜质量(图5和6)及器件制作结果(图7); 4. 利用网络分析仪测试SAW 谐振器电学性能并与仿真结果相比较, 验证SAW谐振器设计仿真方法和MEMS制作工艺的可行性和有效性(图8)。1. 基于耐高温材料AlN/4H-SiC, 成功设计并制作出SAW谐振器(尺寸: 1107 μm×721 μm); 2. 在4H-SiC 上得到了高质量c 轴择优取向的AlN 压电薄膜, 衍射峰为36.10°, 摇摆曲线半高宽仅1.19°; 3. SAW 谐振器电学性能测试结果与仿真结果一致, 证明其设计仿真方法正确有效、MEMS 制作工艺可行。

•SPF is important to fundamentally investigate 2D material's surface energy.•SPF is a generic method which is suitable for different materials.•SPF method can detect the adhesion energy after device fabrication.•SPF is easy to manipulate and unlikely to causes damage to the sample detected.This paper presents a generic approach to characterize and analyze the adhesion energy between graphene and different materials using nanoindentation of an atomic force microscope (AFM), which is extremely essential and critical for variety of graphene based micro- and nano-devices. AFM was used to press a free-standing graphene beam down to a substrate. During the retraction, the adhesion force (named as the secondary pull-off force) was measured to analyze the adhesion energy between the graphene beam and the substrate. This approach is easy for manipulation and it can detect the adhesion energy after the device fabrication. According to our measurement, the graphene/SiO2, graphene/gold, and graphene/graphene adhesion energies per area are approximately 270 mJ/m2, 255 mJ/m2, and 307 mJ/m2, respectively. This result was used to predict the performances and guide the design of graphene M/NEMS devices.