Templated Laser-Induced-Graphene-Based Tactile Sensors Enable Wearable Health Monitoring and Texture Recognition via Deep Neural Network

Abstract

Flexible tactile sensors show great potential for portable healthcare and environmental monitoring applications. However, challenges persist in scaling up the manufacturing of stable tactile sensors with real-time feedback. This work demonstrates a robust approach to fabricating templated laser-induced graphene (TLIG)-based tactile sensors via laser scribing, elastomer hot-pressing transfer, and 3D printing of the Ag electrode. With different mesh sandpapers as templates, TLIG sensors with adjustable sensing properties were achieved. The tactile sensor obtains excellent sensitivity (52260.2 kPa–1 at a range of 0–7 kPa), a broad detection range (up to 1000 kPa), a low limit of detection (65 Pa), a rapid response (response/recovery time of 12/46 ms), and excellent working stability (10000 cycles). Benefiting from TLIG’s high performance and waterproofness, TLIG sensors can be used as health monitors and even in underwater scenarios. TLIG sensors can also be integrated into arrays acting as receptors of the soft robotic gripper. Furthermore, a deep neural network based on the convolutional neural network was employed for texture recognition via a soft TLIG tactile sensing array, achieving an overall classification rate of 94.51% on objects with varying surface roughness, thus offering high accuracy in real-time practical scenarios.

Recent Advances in Tactile Sensory Systems: Mechanisms, Fabrication, and Applications

“…Wearable tactile devices can provide a more natural and realistic touch sensation for the wearer and are used to improve immersion in virtual reality/augmented reality (VR/AR) systems [ 146 , 147 , 148 , 149 , 150 ]. The glove is the bridge connecting virtuality and reality, and is used to send real-time tactile-feedback information.…”

In Situ Growth of Laser-Induced Graphene on Flexible Substrates for Wearable Sensors

“…Flexible electronics that enable real-time and accurate motion capture, health monitoring, and haptic recognition have received widespread attention in wearable electronic devices. Generally, biological signal detection is a complex task, including large body deformations (such as elbow movements, knee bending movements, etc.)…”

Improving the Resolution of Flexible Large-Area Tactile Sensors through Machine-Learning Perception

“…Inspired by human skin, more and more researchers are working to prepare flexible tactile arrays with skin-like functionality to meet the needs of robotic mechanical claw grip state sensing − and have achieved perception capabilities far beyond skin. − Over the past decade, tactile array sensors have been extensively developed by utilizing different sensing mechanisms, such as resistive-, − capacitive-, − and piezoelectric-type mechanisms. − Among them, piezoresistive tactile sensors have become a focus of research due to their high load capacity, low mass production cost, low noise, and high tactile sensitivity. − Recently, advances in various functional materials, − structural designs, ,− fabrication methods, − and signal processing technologies − have further accelerated the development of tactile array sensors, which now enable pressure detection beyond the limits of the skin and ultrawide pressure monitoring ranges. However, some inherent characteristics of array-type tactile sensors limit their application in practical applications.…”