Wirelessly Powered Cage Rx Coil WPT Tx Coil IMD IMD Rx Coil Tx Coils (a) (b) FIGURE 6: Wireless powering scenarios: (a) Tx and Rx coils at a fixed distance and (b) wirelessly powered cage for freely moving animals. magnetic sensors for focused WPT to the randomly moving Rx target. In a previous study [68], the use of Microsoft Kinect devices for optical animal tracking techniques has been explored. This approach not only enables obtaining information about the Rx coil position but also facilitates the analysis of animal locomotion and behavior. Alternatively, in the cage design of [69], the Tx resonators positioned directly below and above the Rx device will be automatically activated, providing a natural mechanism for magnetic field localization of the resonators. Driver Port Th_H S3 S1 25 cm S2 Driver Hex-PSCs Magnetic Sensors (a) (b) Primary Hex-PSCs 61 cm Plexiglas Cage Boundary Th_L Active Area Switching Boundary Stationary Module 15 cm Stationary Module Boundary 58 cm 15 cm 40 20 50 40 30 Y (cm) 20 10 0 0 (c) FIGURE 7: (a) The configuration of the scalable multilayer Tx coil array and (b) the modular design scaled to accommodate an experimental arena with arbitrary dimensions (adapted from [65]). (c) Measured PTE distribution within the cage arena when the Rx is swept at a height of 70 mm (adapted from [66]). hex-PSC: hexagonal planar spiral coil. 36 FALL 2023 IEEE SOLID-STATE CIRCUITS MAGAZINE 20 40 X (cm) 60 PTE (%) WPT