A research team led by Prof. Li Runwei at the Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences, in cooperation with the National Institute for Materials Science in Japan, has developed a flexible tactile sensor that could be used in electronic skins and is able to detect subtle changes such as moving ants.

Electronic skin is a system for the handicapped to restore their tactile sensation. Different from human skin, most electronic skins can only convert external stimuli into analog signals instead of physiological responses, which are transferred to the brain via the nervous system. To address this problem, Prof. Li Runwei, Assoc. Prof. Liu Yiwei and PhD candidate Wu Yuanzhao designed an LC circuit the frequency of which changes with the variation of inductance brought by external stress / strain. The researchers are confident that the circuit could be applicable to electronic skins once it is optimized in accordance with the range of physiological signals in the human body.

In addition, they designed an air gap structure with amorphous wires as its magnetic core. With this design, they developed a digital flexible tactile sensor with a sensitivity of 4.4 kPa-1 and a detection limit of 10 μN (equivalent to 0.3 Pa). By adjusting its modulus and structure, the sensor has a wider detection range. In other words, it can detect both subtle and strenuous events such as moving ants and lifting heavy weights.

With such high sensitivity and superb bionic features, the researchers believe that the tactile sensor has a potential to renovate the situation of the physically challenged by giving them an artificial “tactile organ”.

This work was published in Science Robotics (Sci. Robot. 2018, 3, eaat0429, http://robotics.sciencemag.org/content/3/22/eaat0429.full), and it was supported by various projects and programs including the National Science Fund for Distinguished Young Scholars of China (No. 51525103), the China International Cooperation Project (No. 2016YFE0126700), the National Natural Foundation of China (Nos. 61704177, 11474295 and 61774161) and the Ningbo Science and Technology Innovation Team Program (No. 2015B11001).

(a) Schematic illustration of the operating mechanism of the device (b) Response of the sensor to a pressure of 0.3 Pa (c) The digital-frequency response of the device changed with applied pressure (d) Schematic diagram of the sensor

For more information, please contact:

Wu Yuanzhao

Key Laboratory of Magnetic Materials and Devices

Ningbo Institute of Materials Technology & Engineering

E-mail: wuyz@nimte.ac.cn

Source: Ningbo Institute of Materials Technology & Engineering, CAS