Implantable and ingestible fluid-actuated soft robotic solutions with therapeutic applications

Fluid-powered soft robotics is establishing as the new gold standard in several healthcare-related applications (e.g., wearable rehabilitation devices, artificial organs), both in the scientific literature and in novel commercial devices, thanks to its superior safety and biocompatibility onto or inside the patient's body. This thesis develops different fluidic soft robotic modules in two frontier research fields of therapeutic medicine, aiming at replacing the current clinical solutions, still largely suboptimal. The first is fully-implantable Artificial Lower Urinary Systems (A-LUSs), designed for two widespread and very debilitating conditions: an inactive urinary bladder, mainly due to neurological injuries (A-LUS-1), and the total absence of it, due to cancer (A-LUS-2). The second is ingestible, active capsule robots, capable of performing on-demand localized therapeutic actions at any point of the gastrointestinal (GI) system. This, with traditional endoscopy, is not possible in the deep portion of the small bowel. In particular, different devices of the two modular A-LUSs were designed, fabricated, and validated (personally, or in collaboration). For A-LUS-1, a hydraulic soft robotic actuator based on an origami design was developed, allowing the proper voiding of the embraced inactive bladder (i.e., an artificial detrusor muscle). The device was thoroughly evaluated on 'ex vivo' swine bladders. A model-based design approach for a future, geometrically optimized, and more lightweight hydraulic detrusor is also presented. For A-LUS-2, an anatomically shaped and soft artificial urinary bladder was developed. It was also complemented with a purpose-built hydraulic artificial detrusor and a fully-wireless, quasi-implantable-size, low-power actuation control module, also applicable to other hydraulic artificial muscles. This integrated system was positively evaluated in a simulated human anatomy (mannequin). The bladder only was successfully evaluated 'in vivo' in n = 5 implants in young farm pigs. For the GI district, a safely ingestible, self-deployable, and self-detachable soft capsule robot was designed, fabricated and preliminarily validated. After its biodegradable shell reaches the target location and dissolves at a target pH, the capsule robot can be safely anchored to the GI mucosa via two soft suction cups. Afterwards, two miniature pneumatic actuators powered by onboard CO2 generation cause, sequentially, the release of a liquid drug and the soft robot detachment, allowing its subsequent natural excretion. The compartmental design of the soft capsule robot opens possibilities to embed different therapeutic actions than drug delivery.