Utilisation of a wrinkled film-based structure for the sensing measurement of a vibro-impact capsule robot

Abstract

According to a pre-strain strategy, a wrinkled structure for measuring the contact pressure between the intestinal wall and the vibro-impact capsule robot is proposed for the potential application of early bowel cancer detection. An analytical model of this wrinkled structure is established by using an energy method. Based on Hertz theory, a theoretical expression for the elastic modulus of bowel tissue and the amplitude of this structure, so the current generated, is obtained. It is found that the sensitivity of the structure is dependent on its wrinkled amplitude. Our simulation results show that, for a static capsule, the greater the contact pressure between the wrinkled structure and the capsule is, the greater the current of this mechanism is generated, indicating the bowel tissue becomes stiffer. For a dynamic capsule, our simulation results reveal that the faster the average velocity of the capsule is, the greater the current is generated. These relationships are explained by modelling the hoop pressure of the intestine on the capsule robot validated via finite element analysis. The findings of this paper can provide design guidelines for fabricating the proposed mechanism integrated onto the vibro-impact capsule robot for diagnostic and tracking purposes.