Contact resistance based tactile sensor using covalently cross-linked graphene aerogels

Area of Science:

• Materials Science
• Electrical Engineering
• Mechanical Engineering

Background:

• Movable electrical contacts are fundamental in electronics for binary control.
• Existing sensors often lack the sensitivity and range for complex mechanical force analysis.

Purpose of the Study:

• To develop a sensor utilizing variable contact resistance for non-binary mechanical force measurement.
• To demonstrate superior strain and pressure sensing capabilities using a graphene aerogel-metal electrode interface.

Main Methods:

• Fabrication of a sensor using a highly elastic graphene aerogel and a rigid metal electrode.
• Utilizing changes in contact resistance to quantify compressive and tensile forces.
• High-temperature induced covalent cross-linking of graphene for enhanced material properties.

Main Results:

• Demonstrated superfast (<0.5 ms), ultrasensitive, and quantitative measurements of stress from -1.18 MPa to 0.55 MPa.
• Sensor operates effectively across a wide temperature range (-60 to 100 °C) and covers human motion ranges.
• Successfully determined the weight of grasped objects and showed high durability.

Conclusions:

• Contact resistance-controlled sensing offers high-precision and reliable strain and pressure measurement over a large range.
• The developed graphene aerogel sensor has significant potential for human-machine interfaces, robotics, flexible electronics, and haptic technology.