Magnetic soft robotic bladder for assisted urination

Abstract

The poor contractility of the detrusor muscle in underactive bladders (UABs) fails to increase the pressure inside the UAB, leading to strenuous and incomplete urination. However, existing therapeutic strategies by modulating/repairing detrusor muscles, e.g., neurostimulation and regenerative medicine, still have low efficacy and/or adverse effects. Here, we present an implantable magnetic soft robotic bladder (MRB) that can directly apply mechanical compression to the UAB to assist urination. Composed of a biocompatible elastomer composite with optimized magnetic domains, the MRB enables on-demand contraction of the UAB when actuated by magnetic fields. A representative MRB for a UAB in a porcine model is demonstrated, and MRB-assisted urination is validated by in situ computed tomography imaging after 14-day implantation. The urodynamic tests show a series of successful urination with a high pressure increase and fast urine flow. Our work paves the way for developing MRB to assist urination for humans with UABs.

Actuators for Implantable Devices: A Broad View

“…The most widely reported wireless-powering approach is the use of an electromagnetic field, whose magnitude and direction can be readily programmed for actuator operation [ 179 , 180 , 181 ]. Wireless electrical power, which is particularly promising for battery-free implantables, can be achieved through an implanted energy harvester that converts RF energy collected to mW-level DC output [ 182 , 183 , 184 ].…”

Mechanically-Guided 3D Assembly for Architected Flexible Electronics

“…Owing to the excellent conformability with the biological surfaces of organs, instrumented flexible devices for surgery were developed. ,,,− For instance, the pressing demand of functional integration for catheters in clinics pushed the development of miniaturized flexible electronic devices with various 3D architectures. − A multifunctional flexible surgical instrument in the form of a balloon catheter was developed, capable of temperature sensing, mapping of cardiac electrophysiological signals with a high signal-to-noise (SNR) ratio of 60 dB, as well as in situ treatments using RF electrodes (maximum power 600 mW) for controlled, localized tissue ablations (temperature rise ∼10 °C) (Figure c). In particular, the use of such instruments in live animal models of rabbits was demonstrated.…”

3D printing of thermosets with diverse rheological and functional applicabilities

“…Thermosets such as silicone-/epoxy-based plastics have been abundantly used in engineering, infrastructure, and daily life in the past century due to their excellent mechanical strength, thermal stability, and chemical resistance [1][2][3] . Recent advances in emerging fields such as soft robotics and flexible electronics also call for the application of thermosetting components with intricate structures and multifunctionality [4][5][6][7][8] . To date, the manufacturing of thermosets still heavily relies on mold-based methods that allow the material to cure into its hardened forms in autoclaves or ovens, e.g., casting 3,[8][9][10] , compression molding 1 , and reaction injection molding 3 .…”

“…Recent advances in emerging fields such as soft robotics and flexible electronics also call for the application of thermosetting components with intricate structures and multifunctionality [4][5][6][7][8] . To date, the manufacturing of thermosets still heavily relies on mold-based methods that allow the material to cure into its hardened forms in autoclaves or ovens, e.g., casting 3,[8][9][10] , compression molding 1 , and reaction injection molding 3 . However, these conventional methods usually involve long manufacturing cycle time, low geometric complexity, and cost-prohibitive facilities, which are not amenable to fast prototyping of intricate components and have low efficacy in creating heterogeneous and multi-functional devices (Supplementary Table 1).…”