Tetherless Mobile Micro-Surgical Scissors Using Magnetic Actuation

Current minimally-invasive surgical tools suffer from lack of scalability and restricted access to some surgical sites using a laparoscopic probe. This paper introduces a proof-of-concept prototype of the first completely wireless surgical scissors capable of dexterous motion and cutting in a remote environment as a mobile microrobotic device. The 15 mm untethered surgical scissors are custom made from sharpened titanium sheets with a magnet on each blade for actuating force and control. A super-elastic nitinol wire acts as a restoring spring and results in a simple design with no pin joint which is difficult to fabricate at small sizes. To actuate and control the scissors, a 3D magnetic coil system is used here for testing and demonstration. An external magnetic flux density of 20 mT can be generated using the coils and is used for cutting as well as orienting, moving and closing the scissors. In this first prototype setup, the scissors can generate up to 75 mN of cutting force, and we demonstrate the cutting of agar. As a proof of concept demonstration of the potential use of the scissors as a completely untethered surgical tool, we robotically maneuver the scissors to a target location in a confined environment where they cut through agar and return to their initial position.