Wireless Powered Capsule Robots With a Wide Locomotion Range and Random Orientation via Planar Transmitting Coils

Abstract

Capsule endoscopy and drug delivery hold great promise but are constrained by power supply limitations. This study introduces a battery-free capsule robot powered by wireless power transfer (WPT), utilizing a phase-controlled 2D planar array operating at 6.78 MHz. This setup provides a stable energy supply for a micro capsule robot in a dynamic 3D space. The robot's receiving coils and on-board circuits are optimized to consistently acquire approximately 1 W of power across various positions and orientations. This enhancement significantly boosts the robot's capabilities, including high-resolution imaging and extended wireless communication. We demonstrate that the capsule can capture and transmit high-resolution images via Wi-Fi, and successfully operated in an ex-vivo digestive system, supporting its potential for biomedical applications within the gastrointestinal tract. This research also advances the WPT technology, paving the way for its use in other miniature biomedical devices and expanding their practical applications.