• artificial bladder
• artificial bladder system
• artificial detrusor
• artificial organ
• bellows actuators
• hydraulic actuation
• origami actuators

The urinary bladder is indispensable to collect urine and void upon peripheral nervous system control. However, cancer, neurological disorders and aging can cause a loss in bladder functions. To date, the existing solutions are only partial and disabling in some cases, thus result in a reduced patients quality of life. The present work aims at developing a fully implantable artificial bladder system (ABS) able to store and eliminate urine. The proposed system is a bicomponent device consisting of an artificial bladder integrated with a hydraulically driven mechanism that serves as detrusor system. The actuation is operated through a controller and a micropumping system connected to a reservoir. The ABS is a self-foldable inextensible structure that can hold 300ml. For the voiding strategy two types of hydraulic actuators are proposed: origami and bellows actuator. The former consists of a rigid zigzag skeleton enclosed in a flexible skin and a fluid medium between them. When a negative pressure is applied by removing the fluid, the actuator contracts exerting a pulling force. The latter one is made of a chain of flexible and inextensible interconnected chambers. They are completely flat when there is no fluid inside but elongate producing a pushing force when inflated. After the design optimization, each actuator type is tested on the ABS and the voiding efficiency is evaluated. The bellows actuators showed higher performance achieving an ABS voiding efficiency of 90%.