Recent Progress in Flexible Tactile Sensors for Human‐Interactive Systems: From Sensors to Advanced Applications

Abstract

detection; furthermore, mechanisms or devices to detect other stimuli, such as strain, temperature, and humidity, may be integrated. A tactile feedback system, integrated with a prosthetic hand, was demonstrated in 1974, [2] and since then, a variety of tactile sensors have been actively developed for use in various applications, such as touch screens and robotic hands. Flexible tactile sensors capable of measuring mechanical stimuli via physical contact have attracted significant attention in the field of human-interactive systems. The utilization of tactile information can complement vision and/or sound interaction and provide new functionalities. Recent advancements in micro/nanotechnology, material science, and information technology have resulted in the development of high-performance tactile sensors that reach and even surpass the tactile sensing ability of human skin. Here, important advances in flexible tactile sensors over recent years are summarized, from sensor designs to system-level applications. This review focuses on the representative strategies based on design and material configurations for improving key performance parameters including sensitivity, detection range/linearity, response time/hysteresis, spatial resolution/crosstalk, multidirectional force detection, and insensitivity to other stimuli. System-level integration for practical applications beyond conceptual prototypes and promising applications, such as artificial electronic skin for robotics and prosthetics, wearable controllers for electronics, and bidirectional communication tools, are also discussed. Finally, perspectives on issues regarding further advances are provided.

Gradient Architecture‐Enabled Capacitive Tactile Sensor with High Sensitivity and Ultrabroad Linearity Range

“…human-machine interaction, architectural intelligence, information communication, etc. [1][2][3][4][5][6] Existing flexible tactile sensors can be mainly classified as piezoresistive, capacitive, triboelectric, and piezoelectric according to the working mechanism. [7][8][9][10][11] Among these types, capacitive sensors using a dielectric layer sandwiched between two flexible electrodes possess the comprehensive advantages of simple structure, facile fabrication, low-energy consumption, static/dynamic detection, and precise modification of the device design by analysis of the simple governing equation, etc., and therefore are attractive.…”

A cutaneous receptors-mimicking system for real-time and multimodal detection of tactile stimuli

“…Human skin is considered the most e cient and powerful tactile sensor 1,2 , and hence many studies have been conducted to develop exible electronic skin that emulate the properties of human skin and provide various tactile information, such as force feedback and texture classi cation, which would allow a robot to perform precise and delicate motions [3][4][5][6][7][8][9] . Advances in skin-mimicking tactile sensing technology could provide diverse human-machine interfaces in virtual/augmented reality and the metaverse 10,11 .…”

Full-Textile Human Motion Detection Systems Integrated by Facile Weaving with Hierarchical Core–Shell Piezoresistive Yarns

“…The wearable intelligent system has attracted increasing research interest due to its capabilities of facile interaction with and continuous monitoring of the human body. It has shown great potential in various fields such as personalized health care, electronic skins, human–machine interfaces, humanoid robots, and so forth. − As a necessary perception component, flexible pressure sensors with simple manufacturing steps, efficient integration, and high sensing performances are required in the wearable intelligent system. − Piezoresistive sensors show great advantages over other types of pressure sensors, including a simple working mechanism, easy processing, and relatively low power consumption. − Until now, extensive efforts have been devoted to improving the sensing performances, ranging from designing microstructures to choosing advanced functional and substrate materials. − For flexible piezoresistive pressure sensors, reversible deformation of the contact area or sites arises under pressure, which in turn induces electrical resistance changes. − Although piezoresistive pressure sensors based on film materials and template transfer methods have made significant progress, their unsatisfying breathability and comfortability for prolonged wearing prohibit their extensive application. The inherent characteristics of textile materials, such as comfort, outstanding breathability, cost-effectiveness, brilliant three-dimensional (3D) conformability, and hierarchical microstructures, , make them an attractive candidate for constructing flexible piezoresistive pressure sensors.…”