Yen Min, Lai Yu-Hong, Zhang Chun-Li, Cheng Hou-Yung, Hsieh Yi-Ting, Chen Jhih-Wei, Chen Yi-Chun, Chang Li, Tsou Nien-Ti, Li Jiang-Yu, Chu Ying-Hao
Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan.
Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province & Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, China.
ACS Appl Mater Interfaces. 2020 May 13;12(19):21818-21826. doi: 10.1021/acsami.0c02275. Epub 2020 Apr 28.
The piezoresistive effect has shown a remarkable potential for mechanical sensor applications and been sought for its excellent performance. A great attention was paid to the giant piezoresistive effect and sensitivity delivered by silicon-based nanostructures. However, low thermal stability and complicated fabrication process hinder their practical applications. To overcome these issues and enhance the functionalities, we envision the substantial piezopotential in a zinc oxide (ZnO)/muscovite (mica) heteroepitaxy system based on theoretical consideration and realize it in practice. High piezoresistive effect with giant change of resistivity (-80 to 240%) and large gauge factor (>1000) are demonstrated through mechanical bending. The detailed features of heteroepitaxy, electrical transport, and strain are probed to understand the mechanism of such a giant resistivity change. In addition, a bending model is established to reveal the distribution of strain. Finally, we demonstrate a flex sensor featuring high sensitivity, optical transparency, and two-segment sensing with a great potential toward practical applications. Such an oxide heteroepitaxy exhibits excellent piezoresistive properties and mechanical flexibility. In the near future, the importance of flex sensors will emerge because of the precise control in the automation industries, and our results lead to a new design in the field of flex sensors.
压阻效应在机械传感器应用中展现出显著潜力，并因其优异性能而受到关注。人们十分关注基于硅基纳米结构的巨压阻效应和灵敏度。然而，低热稳定性和复杂的制造工艺阻碍了它们的实际应用。为克服这些问题并增强功能，我们基于理论考虑设想了氧化锌（ZnO）/白云母（云母）异质外延系统中的大量压电势，并在实践中得以实现。通过机械弯曲展示了具有巨大电阻率变化（-80%至240%）和大应变系数（>1000）的高压阻效应。探究了异质外延、电输运和应变的详细特征，以理解这种巨大电阻率变化的机制。此外，建立了一个弯曲模型来揭示应变分布。最后，我们展示了一种具有高灵敏度、光学透明性和两段式传感功能的柔性传感器，具有巨大的实际应用潜力。这种氧化物异质外延表现出优异的压阻特性和机械柔韧性。在不久的将来，由于自动化行业中的精确控制，柔性传感器的重要性将显现出来，我们的研究结果为柔性传感器领域带来了新的设计思路。
