Capacitive Origami Sensing Modules for Measuring Force in a Neurosurgical, Soft Robotic Retractor

In neurosurgery, soft robots have the potential to introduce significant benefits over traditional metal tools for their ability to safely interact with delicate tissues. In this paper, we introduce a proof-of-concept soft, capacitive origami sensing module (OSM) that can measure forces during neurosurgical retraction. Using origami-inspired design and fabrication principles, the OSM is easily folded and integrated within a soft robotic retractor that interacts with brain tissue to generate a surgical workspace upon actuation. We demonstrate the individual OSM signal response to forces and folding. We further characterize the OSM response within a fully-assembled soft robotic retractor to both folding and the application of forces over 0-5 N showing a 0.38 N average prediction error and resolution of 0.25 N. The sensing capability of the retractor is validated on an in-vitro model to demonstrate prediction errors of 0.06 N and the proposed operation during neurosurgery.