Wearable Capacitive Tactile Sensor Based on Porous Dielectric Composite of Polyurethane and Silver Nanowire

Bare finger tactile sensing for edge orientation and contact position using excitation from fingernail

In recording and reproducing skills involving the fingertips, a sensor that measures tactile information of fingertips is important. However, when the sensor covers the finger pad, the inherent sense of touch is compromised. We introduce a new tactile sensor, a pair of a vibration motor and a 6 degrees-of-freedom sensor attached to a fingernail that enables tactile sensing without covering the fingertip. This sensor estimates finger contact information by measuring vibrations caused by an eccentric motor positioned on the fingernail. The time series of the acquired angular velocity and acceleration data were utilized to identify the edge orientation and the contact position of the touching object. The results of the conducted experiments indicated that this setup can simultaneously identify both the edge orientation and the contact position with an accuracy of 71.67%. Potential applications include remote tactile transmission, integration with a robotic finger, and the detection of grasping postures in real objects.

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

Flexible electronics is a cutting-edge field that has paved the way for artificial tactile systems that mimic biological functions of sensing mechanical stimuli. These systems have an immense potential to enhance human-machine interactions (HMIs). However, tactile sensing still faces formidable challenges in delivering precise and nuanced feedback, such as achieving a high sensitivity to emulate human touch, coping with environmental variability, and devising algorithms that can effectively interpret tactile data for meaningful interactions in diverse contexts. In this review, we summarize the recent advances of tactile sensory systems, such as piezoresistive, capacitive, piezoelectric, and triboelectric tactile sensors. We also review the state-of-the-art fabrication techniques for artificial tactile sensors. Next, we focus on the potential applications of HMIs, such as intelligent robotics, wearable devices, prosthetics, and medical healthcare. Finally, we conclude with the challenges and future development trends of tactile sensors.