Large-Area, Crosstalk-Free, Flexible Tactile Sensor Matrix Pixelated by Mesh Layers

Tactile
sensor arrays have attracted considerable attention for
their use in diverse applications, such as advanced robotics and interactive
human–machine interfaces. However, conventional tactile sensor
arrays suffer from electrical crosstalk caused by current leakages
between the tactile cells. The approaches that have been proposed
thus far to overcome this issue require complex rectifier circuits
or a serial fabrication process. This article reports a flexible tactile
sensor array fabricated through a batch process using a mesh. A carbon
nanotube–polydimethylsiloxane composite is used to form an
array of sensing cells in the mesh through a simple “dip-coating”
process and is cured into a concave shape. The contact area between
the electrode and the composite changes significantly under pressure,
resulting in an excellent sensitivity (5.61 kPa–1) over a wide range of pressure up to 600 kPa. The mesh separates
the composite into the arranged sensing cells to prevent the electrical
connection between adjacent cells and simultaneously connects each
cell mechanically. Additionally, the sensor shows superior durability
compared with previously reported tactile sensors because the mesh
acts as a support beam. Furthermore, the tactile sensor array is successfully
utilized as a Braille reader via information processing based on machine
learning.

触觉传感器阵列因其广泛应用于高级机器人技术和人机交互界面等领域而备受关注。然而，传统触觉传感器阵列因触觉单元间的电流泄漏而导致电串扰问题。迄今为止，为解决此问题所提出的方案均需复杂的整流电路或串联的制造工艺。本文报道了一种通过批量化工艺，采用网状结构制备的柔性触觉传感器阵列。通过简单的“浸涂”工艺，利用碳纳米管-聚二甲基硅氧烷复合材料在网状结构中形成传感单元阵列，并固化成凹形。电极与复合材料之间的接触面积在压力作用下发生显著变化，从而在高达600 kPa的压力范围内展现出卓越的灵敏度（5.61 kPa–1）。网状结构将复合材料分隔成有序的传感单元，以防止相邻单元间的电连接，并同时实现机械连接。此外，该传感器相较于已报道的触觉传感器展现出更佳的耐用性，因为网状结构充当了支撑梁。此外，通过基于机器学习的信息处理，触觉传感器阵列成功应用于盲文阅读器。