A new 3D, microfluidic-oriented, multi-functional, and highly stretchable soft wearable sensor

Area of Science:

• Materials Science
• Robotics
• Wearable Technology

Background:

• The increasing demand for wearable devices necessitates advanced soft sensors capable of multi-modal measurements.
• Existing soft sensors often struggle to simultaneously measure stretch, twist, and pressure effectively.
• Current methods frequently rely on materials like EGaIn, which can be costly and less safe.

Purpose of the Study:

• To introduce a novel, fully 3D, microfluidic-oriented, gel-based resistive soft sensor.
• To demonstrate the sensor's capability for simultaneous measurement of stretch, twist, and pressure.
• To present a low-cost, safe, and ubiquitous alternative conductive material for soft sensors.

Main Methods:

• Development of a 3D, gel-based resistive soft sensor utilizing a biocompatible conductive gel.
• Finite Element Method (FEM) simulations to analyze sensor performance.
• Experimental validation including durability testing, body motion tracking (knee, elbow, wrist), and a 3D active foot insole for pressure mapping.

Main Results:

• The sensor demonstrated highly linear (99%) and accurate (>94.9%) responses.
• The sensor maintained stable performance over a four-hour durability test.
• Successful application in body motion sensing and detailed pressure mapping of the foot sole, showing good discrimination.

Conclusions:

• The proposed gel-based soft sensor is a versatile, multi-functional device for measuring stretch, twist, and pressure.
• Its biocompatibility, low cost, and robust performance make it suitable for various applications.
• Potential applications include rehabilitation, smart clothing, soft robotics, gait analysis, and augmented/virtual reality systems.