F3T: A soft tactile unit with 3D force and temperature mathematical decoupling ability for robots

TL;DR

This paper introduces F3T, a soft tactile sensor capable of independently measuring force and temperature through mathematical decoupling, enhancing robotic manipulation and environmental perception.

Contribution

The study presents a novel multi-layered soft sensor with physical and mathematical decoupling of force and temperature signals, improving accuracy and robustness in robotic tactile sensing.

Findings

Successful decoupling of normal and tangential forces in all directions

Accurate temperature measurement unaffected by external pressure

Enhanced robustness against environmental temperature variations

Abstract

The human skin exhibits remarkable capability to perceive contact forces and environmental temperatures, providing intricate information essential for nuanced manipulation. Despite recent advancements in soft tactile sensors, a significant challenge remains in accurately decoupling signals - specifically, separating force from directional orientation and temperature - resulting in fail to meet the advanced application requirements of robots. This research proposes a multi-layered soft sensor unit (F3T) designed to achieve isolated measurements and mathematical decoupling of normal pressure, omnidirectional tangential forces, and temperature. We developed a circular coaxial magnetic film featuring a floating-mountain multi-layer capacitor, facilitating the physical decoupling of normal and tangential forces in all directions. Additionally, we incorporated an ion gel-based temperature sensing film atop the tactile sensor. This sensor is resilient to external pressure and deformation, enabling it to measure temperature and, crucially, eliminate capacitor errors induced by environmental temperature changes. This innovative design allows for the decoupled measurement of multiple signals, paving the way for advancements in higher-level robot motion control, autonomous decision-making, and task planning.