Octopus-inspired suction gripper for Minimally Invasive Surgery

Aimée Sakes, PhD
Delft University of Technology (TU Delft), Netherlands
Webpage: https://dutchsoftrobotics.nl/people/aimee-sakes
Research interests
Biomedical Engineering, Mechanical Engineering, Zoology

Using a traditional tissue gripper for tissue manipulation during Minimally Invasive Surgery (MIS) can be challenging due to the slippery and flexible nature of human tissues. The low coefficient of friction between the gripper’s jaws and the tissue surface requires the use of high contact forces to grip the tissue, which can cause unwanted damage. Instead of using a shape grip, an alternative would be to use a suction gripper. In these devices, a pressure differential is used grip objects. Unfortunately, man-made suction grippers are unable to manipulate soft and irregular objects. In nature, however, suction discs are omnipresent and able to attach to a wide variety of substrates. Therefore, the goal of this study was to develop a bio-inspired suction gripper that is able to manipulate soft tissues during MIS. What makes our design unique is that by taking inspiration from the octopus, we decoupled the suction chamber, that generates the suction force, from the contact surface, that is responsible for seal generation and friction magnification. The contact surface of the tip was manufactured out of silicone (EcoFlex 00-30) and created an air-tight seal with the tissue and enhances frictional support. The suction cup structure combined a textile mesh with flexible ribs and a layer of silicone (Smooth Sil) to provide structural stability of the gripper during actuation. Furthermore, the flexible ribs allowed the suction gripper to fold into a smaller size to allow for insertion and extraction of the suction gripper through a trocar, as well as unfold to increase the maximum attachment force. The suction gripper was tested on gelatin tissue phantoms and animal tissues. The experiments illustrated that our suction gripper outperforms man-made suction discs, as well as currently described suction grippers in literature in terms of attachment force on animal tissues (5.95±0.52N) and substrate versatility.

Dr. ir. Aimée Sakes is an assistant professor at the Biomedical Engineering Department of the faculty Mechanical, Maritime & Materials Engineering (3mE) at TU Delft, where she earned both her MSc and PhD titles with honors (2013, 2017). Her research focuses on the development of bio-inspired soft instrumentation based on shooting and transport mechanisms found in nature, such as the chameleon tongue, ovipositors of parasitic wasps, and snake locomotion. Her work has resulted in a range of novel prototypes, among which a series of innovative impulse catheters, the world’s first steerable 3D-printed bipolar electrosurgical grasper, and a new type of transport mechanism inspired by the ovipositor (egg-laying needle) of parasitic wasps. For her work, she has been awarded the best PhD thesis on a cardiovascular topic, best female PhD Cum Laude of the TU Delft, the journal on Cardio-Vascular Engineering and Technology (CVET) Most Downloaded Article Award, and the Medical Delta Young Talent – Scientist Award.