Events

Date: 6 February 2025   Time: 15:00 - 16:00     

Location: SEMS Seminar Room, 3rd floor, Engineering Building

Title:

Harnessing Non-Smooth Dynamics for Self-Propelled Gastrointestinal Endoscopies with Vibro-Impact Capsules

Abstract:

The rectilinear motion of a capsule can be generated using a periodically driven internal mass interacting with the main body of the capsule as a 'hammer' in the presence of external resistances. At resonance, this 'hammer' enables the capsule to progress efficiently through complex environments without the need for external accessories. This simplicity in mechanical design and control significantly reduces complications associated with traditional external propellers or fins. However, as a non-smooth system experiencing vibrations, frictions, and impacts, the capsule exhibits a rich variety of behaviours known as multistability, where different long-term behaviours co-exist for a given set of parameters. This can pose significant control challenges when specific attractors dominate the dynamics inside the gut. This talk will discuss our journey from mathematical modelling and numerical analysis to optimisation, control, experimental validation, and ex vivo testing. I will focus on the non-smooth dynamics of the system and the fine-tuning of its parameters to optimise progression rate and force generation, presenting both numerical and experimental results to demonstrate its feasibility in lower gastrointestinal endoscopies.

About the speaker:

Yang Liu is a Personal Chair in Dynamics and Control in the Engineering Department at the University of Exeter, the Principal Investigator of the Exeter Small-Scale Robotics Laboratory, an Honorary Lecturer in the Endoscopy Department at the Royal Devon University Healthcare NHS Foundation Trust. He is also a Topical Associate Editor of the Nonlinear Dynamics journal. He obtained his B.Eng. degree in Automation from Hunan University, Changsha, China in 2003, an M.Sc. degree in Control Systems from the University of Sheffield, Sheffield, UK in 2005, and a Ph.D. degree in Control Engineering from Staffordshire University, Stafford, UK in 2010. After joining the University of Exeter in 2016, Professor Liu has been leading the Exeter Small-Scale Robotics Laboratory. His work focuses on the development and control of small-scale robots at millimetre and micrometre scales, targeting the early detection of bowel cancer and its metastasis.