Soft Teeth-Patterned Microfluidic Force Sensor for Laparoscopic Graspers

This work presents a soft microfluidic-based force sensor developed for laparoscopic graspers. The sensor incorporates a teeth-like surface pattern that mimics the gripping surfaces of surgical graspers and features a microchannel with an inverted stepped-triangle cross-sectional geometry optimized for enhanced sensitivity. The fabrication process involves custom 3D-printed molds for PDMS soft lithography, followed by vacuum-assisted filling of the microchannel with Galinstan, a highly conductive liquid metal. When force is applied, the sensor deforms and induces measurable changes in the electrical resistance of the Galinstanmicrochannel. The sensor exhibits a working range of up to 10 N and achieves a sensitivity of $0.019 ~\mathrm{N}^{-1}$. As a demonstration, of the sensor's integration onto the grasping jaws of a laparoscopic grasper enables real-time feedback of grasping forces. This technology holds significant potential for minimizing the risk of tissue damage and improving patient care in minimally invasive surgical procedures.