Investigation of a novel approach for enhancing the sensitivity of flexible stretchable sensors by utilizing V-angle structures

Abstract

Flexible stretchable sensors have great potential in the fields of electronic skin, medical monitoring and soft robot. At present, most sensors are mainly suitable for large strain detection, and the development of sensitive sensors for small strain detection is still a huge challenge. Herein, we fabricated flexible stretchable sensors with V-angle structures by the electrohydrodynamic printing technology to detect small strains. Firstly, single V-angle and multiple V-angle structures were proposed for enhancing sensor sensitivity, and their stress concentration, as well as the angles and numbers of the V-angles, was analyzed by using the Abaqus software to explore its influence on sensor sensitivity. Corresponding experiments were carried out, and the results indicated sensors with V-angle structures could be used to sensitively detect small strains (0.01% small strain detection limit), and decreasing the angle of V-angles or increasing the numbers of V-angles could enhance the sensor sensitivity because of the stress concentration. The highest sensitivity (126.45) was achieved when three V-angles were used and each V-angle was set at 120°. Finally, applications on different human body parts, such as wrist, neck, and mouth, were implemented to verify the feasibility of the proposed sensors in monitoring muscle stretching in real time.