Dense elastomeric liquid metal microcoil-based haptic interfaces for endoscopic teleoperation and remote palpation

Robotic-assisted surgery enhances surgical precision, yet the lack of haptic perception complicates clinical decision-making. Consequently, integrating haptic feedback technology into telemedicine systems has garnered significant attention. Existing haptic actuators suffer from limitations such as high drive voltages or slow response speeds. Electromagnetic actuators either sacrifice flexibility by using high-density rigid coils or increase drive power by employing low-density flexible coils. This work proposes a vacuum-assisted infiltration method that overcomes the constraints of liquid metal (LM) surface tension, enabling the fabrication of high-density 3D LM microcoils with an ultra-high magnetic flux density generation efficiency of 19.86 T·W -1 ·m -2 . By combining a high-magnetization-content soft magnet with a patterned low-modulus soft membrane, a fully elastomeric haptic electromagnetic actuator (EHEA) generates perceptible haptic stimuli at ultra-low power consumption (0.809–2.369 mW), resolving the performance-flexibility conflicts. Integrating the EHEAs with LM strain sensors into a haptic interface enables users to perceive the stiffness of objects during robotic teleoperation. More critically, users can differentiate the physical properties of sigmoid colon cancer lesions during endoscopic teleoperation. This work presents a tangible solution for haptic feedback in remote medical palpation, opening new avenues to reduce diagnostic errors for remote diagnostics and minimally invasive surgery.