School of Aerospace Science and Technology, Xidian University, Xi'an, Shaanxi, 710126, China.
Department of Chemical Engineering and Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa, 3200003, Israel.
Small. 2020 Jun;16(24):e2001363. doi: 10.1002/smll.202001363. Epub 2020 May 10.
Achieving highly accurate responses to external stimuli during human motion is a considerable challenge for wearable devices. The present study leverages the intrinsically high surface-to-volume ratio as well as the mechanical robustness of nanostructures for obtaining highly-sensitive detection of motion. To do so, highly-aligned nanowires covering a large area were prepared by capillarity-based mechanism. The nanowires exhibit a strain sensor with excellent gauge factor (≈35.8), capable of high responses to various subtle external stimuli (≤200 µm deformation). The wearable strain sensor exhibits also a rapid response rate (≈230 ms), mechanical stability (1000 cycles) and reproducibility, low hysteresis (<8.1%), and low power consumption (<35 µW). Moreover, it achieves a gauge factor almost five times that of microwire-based sensors. The nanowire-based strain sensor can be used to monitor and discriminate subtle movements of fingers, wrist, and throat swallowing accurately, enabling such movements to be integrated further into a miniaturized analyzer to create a wearable motion monitoring system for mobile healthcare.
在人体运动过程中实现对外界刺激的高度精确响应，是可穿戴设备面临的一项重大挑战。本研究利用纳米结构固有的大表面积与体积比以及机械坚固性，实现了对运动的高灵敏度检测。为此，我们采用基于毛细作用的机制制备了大面积覆盖的高度取向纳米线。这些纳米线构成的应变传感器具有优异的应变系数（≈35.8），能够对各种细微的外部刺激（≤200 µm 的变形）做出高响应。这款可穿戴应变传感器还具有快速响应速度（≈230 ms）、机械稳定性（1000 次循环）和可重复性、低滞后（<8.1%）以及低功耗（<35 µW）的特点。此外，它的应变系数几乎是基于微丝的传感器的五倍。基于纳米线的应变传感器可用于精确监测和区分手指、手腕和喉咙吞咽等细微运动，使这些运动能够进一步集成到一个小型化分析器中，从而创建一个用于移动医疗保健的可穿戴运动监测系统。
