Colonic locomotion

Colonic locomotion

Dodou, D.

Wieringa, P.A. (promotor)

Mechanical Maritime and Materials Engineering

2006-09-18

The most effective screening method for colonic cancer is colonoscopy. However, colonoscopy cannot be easily embraced by the population because of the related pain intensity. Robotic devices that pull themselves forward through the colon are a possible alternative. The main challenge for such devices is their locomotion method along the slippery colon. This study focuses on devices which regularly switch between high friction to grip and low friction to slide and introduces a new method to manipulate friction by means of mucoadhesives. Mucoadhesives are polymers adhering to the mucus that covers the intestinal surface. We showed experimentally that mucoadhesive films can generate high static friction with the colon. In contrast with Coulomb friction, the static friction increases with the film area. The film geometry is of influence as well. Strikingly, when reducing the area by opening holes within the film structure, static friction can be considerably increased. A theoretical model was developed to express the frictional behaviour of mucoadhesive films. The role of geometry in the static friction offers new outlets to friction manipulation and provides new options for the design of the device. It seems also feasible to expand and apply the idea of increasing and manipulating friction by means of adhesive forces when gripping or handling soft, sensitive, or vulnerable objects. The artifice is to increase the adhesive forces up to a level that friction starts being controlled by adhesion, but without exceeding a ceiling of forces beyond which the adhesive falls into the area of permanent joints.

colonoscopy
friction
adhesion
mucoadhesives

http://resolver.tudelft.nl/uuid:0333b46c-8706-4aeb-b308-b69af9b99cf9

90-9020968-9

Institutional Repository

doctoral thesis

(c) 2006 D.Dodou