Development and Integration of Carbon–Polydimethylsiloxane Sensors for Motion Sensing in Soft Pneumatic Actuators

Abstract

Drawing inspiration from the intricate soft structures found in nature, soft actuators possess the ability to incrementally execute complex tasks and adapt to dynamic and interactive environments. In particular, the integration of sensor data feedback allows actuators to respond to environmental stimuli with heightened intelligence. However, conventional rigid sensors are constrained by their inherent lack of flexibility. The current manufacturing processes for flexible sensors are complex and fail to align with the inherent simplicity of soft actuators. In this study, to facilitate the straightforward and consistent sensing of soft pneumatic actuators, carbon–polydimethylsiloxane (CPDMS) materials were employed, utilizing 3D printing and laser-cutting techniques to fabricate a flexible sensor with ease. The preparation of standard tensile specimens verified that the sensor exhibits a fatigue life extending to several hundred cycles and determined its gauge factor to be −3.2. Experimental results indicate that the sensor is suitable for application in soft pneumatic actuators. Additionally, a printed circuit board (PCB) was fabricated and the piecewise constant curvature (PCC) kinematic method was utilized to enable real-time pose estimation of the soft pneumatic actuator. Compared with computer vision methods, the pose estimation error obtained by the sensing method is as low as 4.26%. This work demonstrates that this easily fabricated sensor can deliver real-time pose feedback for flexible pneumatic actuators, thereby expanding the potential application scenarios for soft pneumatic actuators (SPAs).

Keywords

• soft pneumatic actuators
• flexible sensors
• CPDMS
• PCC
• real-time feedback