基于聚偏氟乙烯的全柔性三维力触觉传感器原理、设计与制备

Developing high performance fully flexible tactile sensors has long been an essential subject for the dexterous robot hand technology. Currently, for the robot tactile sensing technology, one critical issue lies in simultaneously realizing dynamic/static multi-dimensional spatial force detection and full flexibility. Thus, the development of fully flexible multi-dimensional force tactile sensors is still an on-going task. Herein, in this project, we propose a novel fully flexible three-dimensional force tactile sensor based on poly(vinylidene fluoride) (PVDF) . A comprehensive study will be performed concerning the design and fabrication of this novel tactile sensor. Furthermore, the applicability of this tactile sensor in the fingertip of dexterous robot hand will also be explored. In this project, first, we will employ the nanocomposites strategy and advanced micro/nano-machining technology to fabricate three kinds of PVDF based nanocomposites layers with tunable piezoelectricity, piezoresistance and electrical conductivity, respectively. Next, a multi-layer structured sensing unit composed of piezoelectric layer, conductive electrode and piezoresistive layer will be designed and fabricated. Making use of the three-dimensional tunable piezoelectricity and patternized electrodes, the corresponding piezoelectric layer and piezoresistive layer can realize the functions of detecting dynamic and static three-dimensional stress (strain), respectively. By combining the advantages of good dynamic response of piezoelectric layer and low frequency/static response of piezoresistive layer, the obtained sensing unit will be capable of detecting three-dimensional stress (strain) under full-frequency range conditions. Last, a tactile fingertip sensor will be constructed based on these novel sensing units to explore and demonstrate its biomimetic tactile and slip features. Meanwhile, the inversion algorithm for identifying the contact force vector including its normal component and tangential component will also be established. This study is of significant importance from both academia and industry, and the obtained results are expected to open up a new avenue to the design of fully flexible three-dimensional force tactile sensors.

发展高性能全柔性触觉传感器对实现机器人灵巧手具有重要意义。针对目前灵巧手触觉传感器难以兼顾全柔性与空间动静态多维力检测的不足，本项目提出了一种基于聚偏氟乙烯（PVDF）聚合物的新型全柔性三维力传感器的原理与设计，并开展其在灵巧手指尖上的阵列化集成应用研究。首先，利用纳米复合效应与先进微纳加工手段实现基于PVDF的高性能压电、压阻和电极三种功能层及电学各向异性调控；随后采用多层复合设计构筑具有压电层－电极层－压阻层一体化结构的感知单元，利用具有压电各向异性的压电层感知动态三维应力信息，利用电极图案化设计发挥压阻层的低频/静态三维应力传感特性，实现在同一柔性感知单元结构上的全频域动静态三维应力传感功能。在此基础上，合理设计基于此感知单元结构的指尖型触觉传感器，建立触/滑觉力反演算法，验证其仿生触觉/滑觉功能。研究成果有望为全柔性三维力触觉传感器的设计提供新思路，具有重大的科学意义与应用价值。

发展高性能全柔性触觉传感器对实现机器人灵巧手具有重要意义。针对目前灵巧手触觉传感器难以兼顾全柔性与空间动静态力检测的不足，本项目提出了一种基于聚偏氟乙烯（PVDF）聚合物的全柔性力传感器的原理与设计。项目依次进行了PVDF基功能层的成型及电学性能优化、感知单元的设计成型以及触觉力功能验证的工作。首先，结合纳米复合效应与先进微纳加工手段分别实现了基于PVDF的高性能压电、压阻和电极三种功能层的制备以及电学性能的调控，随后采用热压工艺构筑了具有压电层－电极层－压阻层一体化结构的感知单元，最后评估了基于PVDF的各功能层以及感知单元的力触觉传感性能。相较于纯PVDF，利用纳米复合增强效应的压电功能层压电/传感性能可提高1倍以上；利用渗流效应的压阻层传感灵敏度高，检测力范围广；具有一体化结构的感知单元集合了压电/压阻功能层的优点，可实现动、静态力的感知。本项目的研究将为基于PVDF 的动、静态力检测方法奠定理论和实验基础，为全柔性力触觉传感器的设计提供新思路，具有重大的科学意义与应用价值。