A novel fully 3D, microfluidic-oriented, gel-based and low cost stretchable soft sensor

TL;DR

This paper introduces a fully 3D, gel-based, low-cost, highly stretchable resistive sensor capable of measuring stretch, twist, and pressure simultaneously, suitable for wearable and soft robotics applications.

Contribution

The paper presents a novel 3D microfluidic-oriented gel-based sensor that replaces expensive EGaIn with safe, low-cost glycol gel, enabling multi-parameter sensing in a single device.

Findings

Sensor exhibits linear and accurate responses in tests.

Demonstrated durability and functionality on human joints.

Successfully integrated into a foot insole for pressure measurement.

Abstract

In this paper, a novel fully 3D, microfluidic-oriented, gel-based, and low-cost highly stretchable resistive sensors have been presented. By the proposed method we are able to measure and discriminate all of the stretch, twist, and pressure features by a single sensor which is the potential that we have obtained from the fully 3D structure of our sensor. Against previous sensors which all have used EGaIn as the conductive material of their sensor, we have used low-cost, safe, and ubiquitous glycol-based gel instead. To show the functionality of the proposed sensor some FEM simulations, a set of the designed experimental tests were done which showed the linear, accurate, and durable operation of the proposed sensor. Finally, the sensor was put through its paces on the knee, elbow, and wrist of a female test subject. Also, to evaluate the pressure functionality of the sensor, a fully 3D active foot insole was developed, fabricated, and evaluated. All of the results show promising features for the proposed sensor to be used in real-world applications like rehabilitation, wearable devices, soft robotics, smart clothing, gait analysis, AR/VR, etc.