Higher resolution brain mapping tech wins big at Research Expo

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• Katherine Connor- [email protected]

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University of California San Diego electrical and computer engineering PhD student Andrew Bourhis won the top prize at the 42nd annual Jacobs School of Engineering Research Expo for his work to integrate thin film transistors into easier-to-use flexible electrode arrays, which could enable much more precise mapping of human brain activity. He was selected from among more than 160 graduate students from all six Jacobs School of Engineering departments who participated in Research Expo this year. 

Research Expo is unique in that graduate students are judged not just on the technical merits of their research, but also on their ability to effectively communicate its impact to a non-technical audience. More than 110 judges participated this year; most judges are industry professionals, many of whom are also alumni or members of the Jacobs School's Corporate Affiliates Program.

In addition to the $1,500 grand prize, which is called the Lea Rudee Outstanding Poster Award, judges vote on a series of other awards that celebrate research projects from across the Jacobs School. Judges vote to select one student presenter in each of the Jacobs School's six academic departments to receive a $750 Best Poster Award. All attendees vote to select a $500 People's Choice Award recipient. And new this year was a Transdisciplinary Collaboration Award with a $1,000 prize. All recipients are detailed below.

The annual event for alumni, industry partners and faculty to connect, collaborate and meet top-tier graduate students, Research Expo provides students an opportunity to practice communicating the broader significance of their work to a wide audience.

"It is essential as a successful engineer to understand and appreciate the larger context of your work," said Albert P. Pisano, Dean of the Jacobs School of Engineering and Special Advisor to the Chancellor. "It's one thing to be able to say 'I made this widget,' but it's another to be understanding of how that improves the lives of people across the country and around the world. And that's the primary function of engineering - we relieve needs by providing the necessary materials, systems and devices."

Improving flexible neural interfaces

One of the goals for Bourhis' flexible neural interfaces with built-in transistors is to provide much more granular detail on the real-time activity of a subject's brain during surgery, restorative or therapeutic long term brain computer interface (BCI) implants. For surgery, this could enable more precise mapping of the source of epileptic activity and could also guide the removal of pathological tissue through a process called functional mapping. For therapeutic BCI, the technology could also be used to stimulate very specific regions of the brain to prevent an epileptic seizure. For restorative BCI, it could detect movement intention to allow amputees to control a prosthetic limb.

Typical clinical electrode arrays used today must pass wires through the scalp to connect to bulky bedside instrumentation. Having transistors built into the electrode arrays reduces the need for these bulky external wires, which keep patients tethered to a hospital bed, often uncomfortable and prone to developing infection. Reducing the number of wires that connect these electrode arrays to electronics would also enable order-of-magnitude increases in the number of sensors researchers could record from, which would allow for vast improvements in the spatial resolution of the sensor arrays themselves.

"The goal of my research is to develop thin film technologies to improve the spatiotemporal resolution of neural interfaces," said Bourhis, a sixth year PhD student working in the lab of Electrical and Computer Engineering Professor Shadi Dayeh and co-advised by Professor Ian Galton. "The brain has nearly 100 billion neurons, and recording from even a few hundred of them can enable patients to control robotic arms to feed themselves, or play online chess using only their thoughts. We're trying to build a technology that can one day scale up to millions of electrodes and simultaneously scale down each electrode to the size of individual neurons. But in order to do that you really need to integrate transistors into the flexible arrays, and at the same time, you need to make sure the technology is safe and can survive being implanted for years without degrading."

While it is already possible to create nanometer-sized transistors in silicon, the brittle nature of that material makes it mostly incompatible with use on the brain, and often requires bulky encapsulation to protect against biofluid. To create a natively flexible and long-term stable interface, Bourhis and researchers in his lab were inspired by the flexible high-definition display field to develop transistors made out of IGZO (indium gallium zinc oxide) as a semiconductor material instead of silicon. IGZO has excellent electrical characteristics and can be processed at lower temperatures, meaning it can be built off of flexible plastic substrates.

"I've been so fortunate to work with such talented colleagues who all work tirelessly for the betterment of society," said Bourhis. "It's my dream that this research will one day help transform the lives of people currently living with incurable diseases or disabilities."

Jacobs School of Engineering Dean Albert P. Pisano presents Andrew Bourhis with the Lea Rudee Outstanding Poster Award. Photo by Long Truong

A graduate student explains the significance of her research to judges and attendees. Photo by Erik Jepsen.

Torus Washington II won the NanoEngineering Best Poster Award for his research project "Bowls Aren't Just for Cereal: Nanobowl Drug Delivery For Lung Cancer Treatment" Photo by Erik Jepsen