All MoS₂-Based Large Area, Skin-Attachable Active-Matrix Tactile Sensor

Abstract

Large-area, ultrathin flexible tactile sensors with conformal adherence are becoming crucial for advances in wearable electronics, electronic skins and biorobotics. However, normal passive tactile sensors suffer from high crosstalk, resulting in inaccurate sensing, which consequently limits their use in such advanced applications. Active-matrix-driven tactile sensors could potentially overcome such hurdles, but it demands the high performance and reliable operations of the thin-film-transistor array that could efficiently control integrated pressure gauges. Herein, we utilized the benefit of the semiconducting and mechanical excellence of MoS 2 and placed it between high-k Al 2 O 3 dielectric sandwich layers to achieve the high and reliable performance of MoS 2 -based back-plane circuitry and strain sensor. This strategical combination reduces the fabrication complexity and enables the demonstration of an all MoS 2 -based large area (8 × 8 array) active-matrix tactile sensor offering a wide sensing range (1−120 kPa), sensitivity value (ΔR/R 0 : 0.011 kPa −1 ), and a response time (180 ms) with excellent linearity. In addition, it showed potential in sensing multitouch accurately, tracking a stylus trajectory, and detecting the shape of an external object by grasping it using the palm of the human hand.

Full-color active-matrix organic light-emitting diode display on human skin based on a large-area MoS 2 backplane

“…4C and fig. S7) (19). A hand moves via two mechanical modes, the compressive mode (mode 1) and tensile mode (mode 2).…”

Two‐dimensional materials: From mechanical properties to flexible mechanical sensors

“…Herein, we highlight the flexible mechanical sensors, including strain sensors, pressure sensors, and vibration sensors, with high performance on sensitivity, lightweight, portable, durable, and low energy consumption. A flexible strain sensor based on In 2 Se 3 and a large‐sized active‐matrix MoS 2 tactile sensor array are shown in Figure B. Typically, the mechanical sensors are composed of conducting sensing materials, flexible electrode, and stretchable or bendable substrate (eg, Ecoflex, PDMS, PET, PI).…”

“…Optical image of a large‐scale active‐matrix MoS 2 tactile sensor array. Reproduced with permission . Copyright 2016, American Chemical Society.…”

Interfacial Phenomena of Advanced Composite Materials toward Wearable Platforms for Biological and Environmental Monitoring Sensors, Armor, and Soft Robotics

“…Piezoresistive materials are extremely prevalent among strain sensors to precisely measure the correlation between strain applied and the relative resistivity and conductivity. Park et al created an active‐matrix‐driven sensor using MoS 2 thin‐film transistors. An active matrix is an array of individual sensing elements that with embedded circuitry for the transistors .…”

“…The interface for biophysical sensors is of extreme importance, as the relationship between the materials determines the type of response that will occur. Most biophysical sensors function based off of measuring the response of the platform electrically, either measuring relative resistance change or less commonly, current and voltage . A recent platform design for monitoring strain is the incorporation of a conductive material, such as a gold nanoparticle coating, deposited on top of a flexible and porous substrate, such as polyurethane foam .…”