HASEL-Actuated Pneumatic Valve for Image Guided Robotic Systems

Abstract:
Robotic systems for image-guided interventions need to be smaller, more compact, and more flexible in their applicability to gain clinical acceptance. Actuators need to be compatible with medical imaging modalities and at the same time compact enough to be integrated into small robots. HASEL (Hydraulic-Amplified-Self-Healing-Electrostatic) actuators demonstrate significant potential for this application, given their high energy density and straightforward mechanical design, which surpass common mechanical principles. Conventional pneumatic valves are unsuitable for use in Magnetic resonance imaging (MRI), which is why pneumatic actuators are equipped with long supply lines into the MRI control room. This results in long response times, complicating the control of the actuators. The aim of this work is to examine the possibility of a HASEL-actuated pneumatic valve. A valve design has been developed and tested that can be actuated by HASEL actuators. Experiments showed that the valve, under electric signal control, can handle differential pressures exceeding 10 kPa. There is potential for design improvements, particularly in eliminating leaks to increase the valve switching pressure. Final tests of a HASEL actuator in the MRI scanner field confirmed its fundamental MRI compatibility.