State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou 310027, China.
Research Center for Intelligent Sensing, Zhejiang Lab, Hangzhou 311121, China.
ACS Appl Mater Interfaces. 2021 Jan 27;13(3):4560-4566. doi: 10.1021/acsami.0c20392. Epub 2021 Jan 13.
Optical micro/nanofibers (MNFs) can be applied for ultrasensitive tactile sensing with fast response and compact size, which are attractive for restoring tactile information in minimally invasive robotic surgery and tissue palpation. Herein, we present a compact tactile sensor (CTS) with a diameter of 1.5 mm enabled by an optical MNF. The CTS provides continuous readouts for high-fidelity transduction of touch and pressure stimuli into interpretable optical signals, which permit instantaneous sensing of contact and pressure with pressure-sensing sensitivity as high as 0.108 mN and a resolution of 0.031 mN. Working in pressing mode, the CTS can discriminate the difference in the hardness of two poly(dimethylsiloxane) (PDMS) slats (with shore A of 36 and 40) directly, a hardness resolving ability even beyond the human hands. Benefitting from the fast response feature, the CTS can also be operated in either scanning or tapping mode, making it feasible for hardness identification by analyzing the shape of the response curve. As a proof of concept, the hardness discrimination of a pork liver and an adductor muscle was experimentally demonstrated. Such MNF-enabled compact tactile sensors may pave the way for hardness sensing in tissue palpation, surgical robotics, and object identification.
光学微/纳光纤（MNFs）可用于超灵敏触觉感应，具有快速响应和紧凑尺寸，这对于恢复微创手术和组织触诊中的触觉信息很有吸引力。在此，我们提出了一种由光学 MNF 实现的直径为 1.5 毫米的紧凑触觉传感器（CTS）。该 CTS 提供连续读数，可将触摸和压力刺激高保真地转换为可解释的光学信号，从而能够即时感应接触和压力，其压力感应灵敏度高达 0.108 mN，分辨率为 0.031 mN。在按压模式下，该 CTS 可以直接区分两个聚二甲基硅氧烷（PDMS）薄片（邵氏 A 硬度为 36 和 40）之间的硬度差异，其硬度分辨能力甚至超过人手。得益于快速响应的特点，该 CTS 还可以在扫描或敲击模式下工作，通过分析响应曲线的形状来实现硬度识别。作为概念验证，实验证明了该 CTS 能够区分猪肝和扇贝的硬度。这种基于 MNF 的紧凑触觉传感器可以为组织触诊、手术机器人和物体识别中的硬度感应铺平道路。
