Towards Internet of Implantable Things: A Micro-Scale Magnetoelectric Intra-Body Communication Platform

Towards Internet of Implantable Things: A Micro-Scale Magnetoelectric Intra-Body Communication Platform Wirelessly connected networks of implantable medical devices with sensing and actuation capability hold the promise of unprecedented real-time healthcare monitoring and therapies that can transform societal health and well-being. In such systems, implants can measure critical physical and physiological parameters, such as mobility, heart rate, neural activity, and chemistry. Based on this data, the system can act to prevent the onset of critical health events or treat diseases in many applications, such as drug delivery, closed-loop neural prostheses, etc. For this vision to be successful, a paradigm shift from conventional standalone highly invasive implants to wirelessly connected networks of miniaturized implants (i.e., Internet of Implantable Things) is of paramount importance. Multiple unresolved challenges exist within current state-of-the-art techniques for intra-body communication that includes radio frequency, inductive, ultrasound, and human body communication. These challenges are: high power consumption, short communication range, low data rate, and large implantable transmitter/receiver transducers. Novel micro-scale implantable methods that enable low-power intra-body communication across long distances (meter) at Mega bits-per-second (Mbps) rates are needed. The proposed research will demonstrate a unique building block for a comprehensive set of wirelessly connected minimally invasive implants that will enable real-time healthcare monitoring and therapies. It will open opportunity for conducting unprecedented neuroscience and electrophysiology experiments that address the most basic questions about the complex nervous system. This program also includes a significant educational and outreach component by taking advantage of the multidisciplinary nature of the research to impact K12 teachers and students, minorities, and undergraduate and graduate students. K-12 teachers and students will be hosted in summers and supported with multidisciplinary classroom research projects, engineering modules, and hands-on opportunities closely coupled to the proposed research.

The proposed Internet of Implantable Things are envisioned to be minimally invasive, fully wireless, and highly connected to address existing challenges within current state-of-the-art techniques for intra-body communication, such as high-power consumption, short communication range, low data rate, and bulky transmitters/receivers. The main objective of this program is to enable wideband, long-range, and low power wireless communication among a network of miniaturized biomedical implants through the use of MHz-range magnetic fields coupled with implantable micro-scale magnetoelectric transducers. The overarching target is to simultaneously provide several Mbps data rate and whole-body communication range with pico-joule-per-bit (pJ/bit) level of energy consumption while dramatically reducing the implant's size. Low-frequency magnetic fields are attractive because of their very low absorption in human tissue and safety. Systematic investigations will be conducted to understand the fundamental behavior of implantable micro-scale magnetoelectric transducers operating at tens of MHz and interfaced with custom-designed pulse-based transceiver circuits for energy-efficient and robust intra-body communication. Effects related to implants' crosstalk, alignment, orientation, and tissue interaction uncertainties in ambulatory subjects will be overcome through innovative magnetoelectric transducer and circuit design. Extensive characterization will be conducted to elucidate the influence of material microstructure and anisotropy, transducer operating mode, alignment, orientation, and tissue interactions on the performance. High accuracy computational and circuit models for magnetoelectric transducers at different tissue medium will be developed and experimentally validated, which will serve as a basis for broad range of system design. The program will provide foundational basis for a novel modulation technique, termed Ultrasound Harmonic Modulation, along with a transceiver chip for micro-scale magnetoelectric transducers. This will lead to a first-in-class micro-scale implantable platform for channelized energy-efficient meter-range communication at safe MHz-range frequencies. System-level demonstrations with different magnetoelectric transducers (dimensional range of 0.1-1 millimeter) and frequencies (10-100 MHz) enabling communication up to meter range at Mbps with pJ/bit power consumption will establish the fundamental basis for the Internet of Implantable Things.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.