Summary:
UCLA researchers in the Department of Electrical and Computer Engineering have developed a dual-coil wireless power and data transfer floor for battery-free implantable devices in freely moving rodents, enabling long-term behavioral and physiological studies in standard animal research chambers.
Background:
Traditional implantable medical devices (IMDs) used in preclinical animal studies are often tethered or battery-powered, which can restrict natural movement, increase device size, and introduce surgical and operational limitations. Wireless power transfer (WPT) systems have emerged as promising alternatives for enabling untethered physiological and behavioral experiments in freely moving animals. However, existing wireless cage systems typically suffer from limited power transfer efficiency, bulky hardware requirements, poor compatibility with standard behavioral chambers, or reliance on complex localization and control systems.
Current wireless cage architectures — including single transmitter coils, scalable coil arrays, and slanted resonating coil systems — each present trade-offs between coverage area, efficiency, scalability, and implementation complexity. Many systems also require substantial external RF hardware or customized enclosures, limiting adoption in standard laboratory environments. Consequently, there remains an unmet need for a compact, scalable, and efficient wireless power and data transfer platform that integrates seamlessly into standard rodent behavioral chambers while supporting reliable operation of miniaturized implants in freely moving animals.
Innovation:
To address these limitations, Professor Aydin Babakhani and his research team have developed a dual-coil antenna floor operating at 13.56 MHz for wireless power and bidirectional data transfer to miniaturized implantable devices in freely moving rodents. Designed specifically for integration into standard behavioral study chambers, the system enables fully wireless and battery-free operation of implantable devices without restricting animal movement. The antenna floor utilizes a dual-coil architecture optimized for power transfer efficiency, ventilation compatibility, and seamless integration into conventional rodent chamber racks. Fabricated using standard PCB technology, the platform supports a wireless coverage area of approximately 25 cm × 28 cm × 10 cm while maintaining strong impedance matching performance of -21 dB with 2 W external input power. A flexible 15 mm circular implantable receiver coil enables wireless powering and control of implanted devices.
To validate the platform, the researchers demonstrated wireless Vagus nerve stimulation (VNS) in freely moving rats using a miniaturized implant. The system successfully achieved heart rate modulation exceeding 80 bpm under varying VNS parameters while maintaining unrestricted movement throughout the chamber. A portable handheld controller communicates wirelessly with a user PC via Bluetooth, enabling flexible programming and control of stimulation parameters. This technology represents a simple, scalable, and reproducible platform for future long-term behavioral, neurological, and physiological studies requiring wireless implant operation.
Potential Applications:
● Wireless Vagus nerve stimulation (VNS) studies
● Freely moving rodent behavioral experiments
● Long-term physiological monitoring
● Neural stimulation and neuromodulation research
● Drug addiction and fear conditioning studies
● Wireless implant validation platforms
● Preclinical bioelectronic medicine research
● Battery-free implantable medical devices
Advantages:
● Fully wireless and battery-free operation
● Compatible with standard rodent behavioral chambers
● Enables unrestricted animal movement
● Dual-coil architecture optimized for power transfer efficiency
● Simplified and scalable implementation
● Wireless power and bidirectional data transfer
● Portable Bluetooth-enabled system control
● Fabricated using standard PCB technology
● Suitable for long-term animal studies
Development-To-Date:
The dual-coil wireless antenna floor has been fabricated and experimentally validated in freely moving rats using wireless Vagus nerve stimulation and heart rate modulation studies.
Related Publications:
• Mathews, R.P., Habibagahi, I., Jafari Sharemi, H. et al. A closed loop fully automated wireless vagus nerve stimulation system. Sci Rep 15, 27856 (2025). https://doi.org/10.1038/s41598-025-11159-8
• Habibagahi, Iman; Omidbeigi, Mahmoud; Hadaya, Joseph; Lyu, Hongming; Jang, Jaeeun; Ardell, Jeff; Bari, Ausaf A. AB, MA, MD, PhD; Babakhani, Aydin. 149 Quantitative Performance Assessment of a Wirelessly Powered Vagus Nerve Stimulator in a Porcine Model. Neurosurgery 69(Supplement_1):p 39, April 2023. | DOI: 10.1227/neu.0000000000002375_149
• I. Habibagahi, J. Jang and A. Babakhani, "Miniaturized Wirelessly Powered and Controlled Implants for Vagus Nerve Stimulation," 2022 IEEE Radio Frequency Integrated Circuits Symposium (RFIC), Denver, CO, USA, 2022, pp. 51-54, doi: 10.1109/RFIC54546.2022.9863172.
• Habibagahi, I., Omidbeigi, M., Hadaya, J. et al. Vagus nerve stimulation using a miniaturized wirelessly powered stimulator in pigs. Sci Rep 12, 8184 (2022). https://doi.org/10.1038/s41598-022-11850-0
Reference:
UCLA Case No. 2025-313
Lead Inventors:
Aydin Babakhani, Iman Habibagahi