Breakthrough LM/CNT/FSR Composite Enables High-Sensitivity Flexible Capacitive Sensors for Robotics

A groundbreaking study published in a leading materials journal demonstrates that fluorosilicone rubber (FSR), traditionally used for seals and gaskets, can be transformed into a high-performance dielectric material for flexible capacitive pressure sensors—the "electronic skin" essential for next-generation robotics.

Researchers developed a novel hybrid filler system combining liquid metal (LM) and carbon nanotubes (CNTs) via an ultrasonic-assisted process. The resulting LM/CNT hybrids were incorporated into a fluorosilicone rubber matrix, achieving exceptional synergistic effects.

The LM/CNT/FSR nanocomposite delivered impressive performance metrics: a dielectric constant of 28.83 at 1 kHz, a low dielectric loss tangent of just 0.38, and a low elastic modulus of 1.82 MPa. This combination of high dielectric constant and low loss, coupled with excellent flexibility, has historically been difficult to achieve in dielectric elastomers.

The corresponding flexible capacitive sensor demonstrated a sensitivity coefficient of 0.354 kPa⁻¹, a response time of 260 ms, and stable performance over 1,000 cycles. These characteristics make it suitable for robotic tactile sensing, wearable health monitors, and human-machine interfaces.

With the rapid development of humanoid robotics, the demand for high-performance "electronic skin" is expected to surge. Fluorosilicone rubber's inherent resistance to oils, solvents, and extreme temperatures gives it a distinct advantage over conventional elastomers in this emerging application space.