UC San Diego

Soft robots have rapidly evolved over the past decade due to significant advancements in sensing, actuation, control, material science, and manufacturing methods. These developments, combined with the inherent ability of soft robots to safely conform to delicate environments, have made them promising for a wide range of applications, including minimally invasive surgeries (MIS). However, to fully realize the potential of soft robots as effective systems for surgical applications, there are several remaining challenges, including: First, soft robots must be designed to meet the clinical needs of the specific target procedure, while simultaneously offering significant improvements in safety. However, the compliance offered by soft robots can also cause them to become unstable during surgical tasks that place significant loads on the robot's body. Second, highly deformable soft robots are less intuitive to control than rigid robots, complicating human-in-the-loop teleoperation for surgical applications. Finally, soft robots are generally pneumatically actuated to achieve the high forces and bandwidth needed for many surgical applications. However, this actuation method requires dedicated electromechanical components, such as pressure regulators, MOSFETs, and switches, for each actuator, making the system bulky, expensive, and limiting the robot's ability to operate untethered.

This dissertation presents several new robotic systems designed to address these challenges. First we introduce the InchIGRAB, a soft robot designed for colonoscopy. The InchIGRAB sits inside a vine robot (or growing robot) and is designed to enable navigation of the entire length of the colon during both forward motion and retraction, while minimizing interaction with the delicate colon environment. We also detail the design and modeling of soft, positive-pressure actuated suction cups for anchoring flexible and continuum robots during minimally invasive surgeries. Second, to enable intuitive control of soft and continuum robots, we present Hapstick, a soft, flexible joystick that can render stiffness information to users via fiber jamming. Hapstick was demonstrated as an input interface for teleoperating a continuum robot in colorectal cancer screening tasks. Finally, we present the PneuSIC Box, a pneumatic demultiplexer that enables independent control of multiple pneumatic actuators using a single pneumatic input and a motor. We demonstrated how PneuSIC Box could be used to provide independent control of actuators in an inchworm like robot, similar to the InchIGRAB, and a soft robotic hand. Overall, this dissertation presents several new robotic systems that advance the potential of soft robots for minimally invasive surgical applications