Alumni Magazine

10 years of wearable device breakthroughs

As the ASSIST Center graduates from National Science Foundation funding, researchers look to a self-sustaining future and advancements in implantable devices.

December 7, 2022 Engineering Communications 6-min. read

Two students at lab work table soldering electronics.

Ten years since its founding, the Advanced Self-Powered Systems of Integrated Sensors and Technologies (ASSIST) Center led by NC State has made groundbreaking advances in wearable health monitoring devices.

The center, established in 2012 with the goal of advancing fundamental science in energy harvesting and storage, low-power sensing and low-power electronics, is now increasing its focus on implantable devices as it moves toward a self-sufficient future while building on current initiatives.

A hybrid biophotonic/electrochemical platform wearable device. — ASSIST has developed a Hybrid biophotonic/electrochemical platform that can simultaneously measure heart rate, oxygenation, lactate, cortisol and ph. The goal is to have multimodal sensing of as many parameters as possible. Correlation of multiple biomarkers can provide insight into cardiovascular health, stress, metabolic health and more.

“It took us a while to get the systems together, and it took even more time to make them robust and solid,” said Veena Misra, director of ASSIST and MC Dean Distinguished Professor in the Department of Electrical and Computer Engineering (ECE). “Now we have a prototyping lab, a systems integration team and a thriving education program. … One of the most exciting things I think we can do is take our systems we’ve built and help patients.”

ASSIST is the third National Science Foundation (NSF)-funded Engineering Research Center (ERC) led by NC State, which is one of only two institutions to lead two ERCs at the same time. The Future Renewable Electric Energy Delivery and Management (FREEDM) Systems Center graduated from NSF funding in 2018.

ERCs are funded for 10 years by the NSF and are reviewed annually. NC State led ASSIST with collaboration from researchers at Florida International University, Pennsylvania State University and the universities of Virginia, Michigan, North Carolina, Notre Dame and Utah.
Moving forward, ASSIST will be funded through large grant proposals, support from existing and new industry partners and non-research sources of revenue.

“Now that we’re in self-sufficiency, we can look into other avenues that can be useful,” Misra said. “Getting into implantable devices, or wearables and implantables working together, is an interesting concept. Faculty (members) are also looking at other applications of our technology in agriculture, internet of things and veterinary medicine.”

Changing health monitoring

ASSIST’s primary research initiative is the development of flexible, self-powering and wearable devices that will help monitor a range of health indicators. In the last 10 years, researchers have made several generations of health and environmental trackers (HET) that are used for monitoring asthma, diet and wound healing. Some of these are just a few years away from use by patients and physicians.

HET Gen 1, which monitors users’ health and environment to predict and prevent asthma attacks, is the center’s most mature platform. Users wear a wristband that detects pulse, activity levels, ozone exposure and volatile organic compounds (VOC), as well as a chest patch that monitors heart rate, heart rate variability and cough. These have helped researchers find a correlation between ozone exposure and physiological effects in individuals with asthma compared to those who do not have asthma.

Screen-printed dry electrodes worn above elbox of left arm. — ASSIST’s self-powered electrocardiogram monitoring platform is made of screen-printed dry electrodes on a stretchable armband.ASSIST is working toward it being self-powered by body heat and/or solar sources.

ASSIST’s second-generation HET is a modular and flexible platform that can be integrated into biochemical sensors to monitor lactate, glucose and uric acid.

ASSIST researchers have made industry-changing breakthroughs in flexible devices, especially in its state-of-the-art thermoelectric generators (TEGs). These harvest energy from the temperature difference between the body and surrounding air to power ASSIST’s sensors. Through an NSF Partnerships for Innovation grant, ASSIST is focused on manufacturing these TEGs for broader use.

Over the last decade, ASSIST has been highly entrepreneurial, and its technologies have led to 10 startups. The center has also closely partnered with several companies, including Murata, a biotechnology company. Murata funded research on liquid metal patterning done by Michael Dickey, Camille and Henry Dreyfus Professor in the Department of Chemical and Biomolecular Engineering.

Murata’s involvement with ASSIST began in 2014. Over the years, Murata deepened its involvement with the center — from evaluating ASSIST technologies, to providing perspective and direction as a member of the Industry Advisory Board, to working directly with students and sponsoring research.

“The Murata and ASSIST relationship took time to incubate and find the correct research and project topic alignment,” said Mark Waugh, senior manager, corporate technology and innovation. “The last five years of the relationship continued to grow with activities including sponsored research, white papers, conference papers, ECE senior design projects and webinars.“

Through this partnership, ASSIST received access to Murata’s technology and materials expertise, guidance on market readiness and mentoring from an established industry leader. Murata has benefitted through connections to a tremendous talent pool, including students who have gone on to work for the company, and to leading faculty members, in addition to access to cutting-edge research and intellectual property and spin-off entities.

Zero-power sweat extraction patch. — A flexible zero-power sweat extraction patch that allows monitoring of biochemical markers in sweat without the patient needing to actively be sweating or exercising.

From wearable to implantable

One of ASSIST’s new priorities is the development of implantable health monitoring devices. As of September 2022, Alper Bozkurt, professor in ECE, is the new deputy director of the ASSIST Center. He succeeds Mehmet Ozturk, who had served in the role since 2015 and is also an ECE professor. Bozkurt will be leading the center’s transition to implantable devices, which is a natural step from ASSIST’s work on sensors, circuits, communications and energy storage and transfer in wearable devices.

“It is important to note that we have a very strong College of Veterinary Medicine and medical schools in the area, in addition to ASSIST’s strength in novel biomedical instrumentation,” Bozkurt said. “This brings supply and demand together where a number of implantables applications emerge for animal and human medicine spaces.”

Wound monitoring bandage. — a Wound monitoring bandage that detects uric acid and ph levels in wound exudate to help medical professionals monitor the progression of healing in chronic wounds.

ASSIST has developed several implantable devices, with funding from NSF. Researchers are using ultrasound to power implantable devices made of ASSIST’s novel material and sensing technologies that can be used to monitor cardiac health. ASSIST faculty members aim to demonstrate and evaluate ultrasonic, biomaterial and bioelectronic components of cardiac implantable systems through benchtop and in-vivo experiments, and will eventually assemble the components and continue in-vivo and in-vitro experiments with the complete device.

Through industry funding, researchers have also developed implantable devices to monitor farm, companion and working animals to understand and improve their welfare. Researchers aim to miniaturize versions of wearable health monitoring devices — like health-tracking smart watches — into microchip implants that can be injected under animals’ skin.

Ideas for and from everyone

Throughout its 10 years, ASSIST has prioritized professional development opportunities, such as a workshop this spring on implantable devices, as well as outreach for students from kindergarten through college, offering summer camps, undergraduate research positions and programs for middle and high school students. Education goes hand-in-hand with ASSIST’s research.

Elena Veety, education director for ASSIST and teaching assistant professor in ECE, said these initiatives will continue and expand.

One of its most successful K-12 programs is the Wearable Device Challenge. Teachers who participate in the NSF Research Experiences for Teachers at the ASSIST Center task their students with designing and building a wearable device.

“They do some really unique things,” Veety said. These unique things include a glove that helps alleviate arthritis, a posture detection device and a gait rehabilitation device worn on a sock.

These are all ideas in the same vein as what ASSIST faculty members are developing and researching — and the students devising them might be among the people continuing ASSIST’s foundational research as the center looks to the next 10 years and beyond.