A breakthrough in bioelectronics has the potential to transform clinical evaluation and treatment
CAMBRIDGE, MA – Ingestible biosensors that can reside in the body for long periods of time hold the promise of radically transforming drug delivery and clinical treatment and evaluation. Such devices could be used to sense conditions in hard to reach places, like the gastrointestinal tract, or carry small reservoirs of drugs to be delivered over an extended period.
But the challenge of how to power these implantable devices has stymied researchers because of the difficulty in finding a safe and efficient power source.
Batteries have proven to be incompatible with the mucosal lining of the gastrointestinal tract and have a limited lifespan within the body. Near-field wireless transmission, which has been used in cochlear implants, requires a distance between two antennas—one inside the body, one outside—proportional to their diameters, that is too limited in range.
Researchers at Draper, MIT and Brigham and Women’s Hospital approached this challenge by demonstrating that a novel remote-charging method called midfield transmission could be relevant to in-vivo applications. Power from an antenna outside the body is transmitted to another antenna inside the digestive tract, yielding enough power to run sensors that can monitor heart rate, temperature and levels of particular nutrients or gases in the stomach. It can also provide power to sensors that serve as drug delivery vehicles and that can remain in the digestive tract for weeks or months.
The research, conducted on a pig, was recently published in the journal Scientific Reports.
“Ingestible biosensors hold great promise for a range of applications and could only have come about because of advancements in subthreshold electronics, low-power systems-on-a-chip and novel packaging miniaturization,” said Brian Smith, co-author on the paper and principal member of the technical staff at Draper.
Draper’s bioelectronics devices build on expertise developed over many years. Draper’s component-level innovations include zero-power and energy-scavenging Microelectromechanical Systems (MEMS) sensors, RF antennas that operate near the fundamental limits of efficiency versus size, smart antennas that adapt to environmental detuning and novel materials to enable lower-loss RF passives. Newer efforts strive to address fundamental limits, such as a program in which Draper will develop litz wire for RF inductors by braiding submicron-scale wires using a self-assembly and directed assembly process exploiting the specific binding properties of organic molecules.
Draper develops precision instrumentation systems that exceed the state-of-the-art in key parameters (input range, accuracy, stability, bandwidth, ruggedness, etc.) that are designed specifically to operate in our sponsor’s most challenging environments (high shock, high temperature, radiation, etc.). As a recognized leader in the development and application of precision instrumentation solutions for platforms ranging from missiles to people to micro-Unmanned Aerial Vehicles (UAVs), Draper finds or develops state-of-the-art components (gyros, accelerometers, magnetometers, precision clocks, optical systems, etc.) that meet the demanding size, weight, power and cost needs of our sponsors and applies extensive system design capabilities consisting of modeling, mechanical and electrical design, packaging and development-level testing to realize instrumentation solutions that meet these critical and demanding needs.
Draper has designed and developed microelectronic components and systems going back to the mid-1980s. Our integrated, ultra-high density (iUHD) modules of heterogeneous components feature system functionality in the smallest form factor possible through integration of commercial-off-the-shelf (COTS) technology with Draper-developed custom packaging and interconnect technology. Draper continues to pioneer custom Microelectromechanical Systems (MEMS), Application-Specific Integrated Circuits (ASICs) and custom radio frequency components for both commercial (microfluidic platforms organ assist, drug development, etc.) and government (miniaturized data collection, new sensors, Micro-sats, etc.) applications. Draper features a complete in-house iUHD and MEMS fabrication capability and has existing relationships with many other MEMS and microelectronics fabrication facilities.
Draper’s Biomedical Solutions capability centers on the application of microsystems, miniaturized electronics, computational modeling, algorithm development and image and data analytics applied to a range of challenges in healthcare and related fields. Draper fills that critical engineering niche that is required to take research or critical requirements and prototype or manufacture realizable solutions. Some specific examples are MEMS, microfluidics and nanostructuring applied to the development of wearable and implantable medical devices, organ-assist devices and drug-delivery systems. Novel neural interfaces for prosthetics and for treatment of neurological conditions are being realized through a combination of integrated miniaturized electronics and microfabrication technologies.
Draper continues to develop its expertise in designing, characterizing and processing materials at the macro-, micro- and nanoscales. Understanding the physical properties and behaviors of materials at these various scales is vital to exploit them successfully in designing components or systems. This enables the development and integration of biomaterials, 3D printing and additive manufacturing, wafer fabrication, chemical and electrochemical materials and structural materials for application to system-level solutions required of government and commercial sponsors.