Startup’s New Type of Magnetic Sensor Could Make High-Performance Brain Imaging More Affordable and Portable

Sonera Magnetics cofounders Dominic Labanowski [left] and Nishita Deka.
Photo: Berkeley Lab
Sonera Magnetics cofounders Dominic Labanowski [left] and Nishita Deka.

By: Prachi Patel

THE INSTITUTE Growing up in San Diego, Nishita Deka enjoyed science, art, and building contraptions with K’nex construction toys. Up until high school, she wanted to be a pediatrician, but then she found herself enjoying her physics classes a lot more than biology. Pursuing a bachelor’s degree in electrical engineering with a minor in physics, she decided, would allow her to expand her skill set and “be a launching pad for whatever I wanted to do later on.”

With her startup, Sonera Magnetics, Deka, an IEEE member, has found a way to combine her interests in medicine, physics, and engineering. The company, based in Berkeley, Calif., is developing a new type of magnetic sensor that it hopes will make high-performance brain imaging more affordable and portable.

“We are trying to detect brain activity using cheaper, faster methods that are still high-performance,” she says. “That’s our North Star. We do a kind of functional imaging, a direct imaging of activities in the brain.”

Brain sensing is commonly done today using electroencephalography, which detects the electrical signals from neurons firing in the brain via electrodes placed on the scalp. EEG can help diagnose epilepsy, brain damage, tumors, and sleep disorders. But electrical signals weaken as they pass through brain fluids and the skull, so the signal outside the brain is fairly low quality.

Magnetoencephalography, which senses the magnetic fields produced by the brain’s electrical impulses, has a much higher spatial resolution. But MEG machines typically rely on superconducting sensors that need to be cryogenically cooled to -270 °C. They also require bulky metal shielding to block out external magnetic signals such as Earth’s magnetic field. The large machines can cost up to US $3 million each, and to power and maintain them costs tens of thousands of dollars every year, Deka says.

Sonera is developing sensors that do not require such cooling. The sensors leverage the strong interaction between magnetic thin films and high-frequency sound waves to measure weak magnetic fields. The solid-state magnetic sensors could lead to room-temperature MEG systems that do not require shielding—enabling faster, less expensive imaging of brain activity without sacrificing accuracy.

“It could change how MEG is used entirely and make it much more accessible,” says Deka, who is developing the technology with cofounder Dominic Labanowski, the company’s chief technology officer.

Only 40 or so MEG machines are installed in U.S. hospitals and research centers today, Deka says. Neurosurgeons typically use them to scan an epilepsy patient’s brain before surgery to pinpoint the location of epileptic activity.

A portable MEG system could pave the way for easier remote monitoring of patients for days and weeks, giving accurate diagnoses of chronic conditions such as epilepsy, or for sleep tracking, Deka says.

The technology ultimately could benefit basic neuroscience, she says, by allowing scientists to see “what’s going in the brain when people are just doing regular daily activities in their normal environment.”

Or it could open up entirely new applications down the road. EEG, for instance, is being studied for brain-control interfaces, which would allow people to use their brain signals to control devices; MEG, because of its higher resolution, would enable more sensitive brain-control devices.

LEARNING CURVE

Deka says she always has been interested in understanding the fundamentals of how things work. Her parents, who both studied physics, encouraged her scientific curiosity, as did her high school physics teacher. At the University of Southern California, in Los Angeles, she conducted undergraduate research in IEEE Senior Member Andrea Martin Armani’s laboratory, making and characterizing silicon chip-based microlasers that are used for detecting nanoparticles and in optical communications. Armani was influential in Deka’s decision to go to graduate school.

Deka went on to earn a doctorate in electrical engineering and computer sciences in 2019 at the University of California, Berkeley. Her graduate research project focused on the development of nanoscale devices for high-voltage switching and portable electron sources for sensing applications.

While at UC Berkeley, Deka met Labanowski, who was researching device applications of acoustically driven ferromagnetic resonance, which is the coupling between magnetic materials and high-frequency sound waves. The two researchers’ ideas and values clicked, and the duo teamed up with Labanowski’s Ph.D. advisor, Sayeef Salahuddin, an IEEE Fellow, to launch Sonera Magnetics in 2018.

The team’s science was sound, but they quickly encountered hurdles inherent in technology development.

“One big challenge is that developing new hardware takes a lot of time, even just to demonstrate basic capabilities,” Deka says. “Another is raising capital.”

Then there was the unexpected learning curve of going from graduate student to business executive—“learning business skills and thinking about the company as not just a technical problem but also a business challenge,” she says.

To get a boost, the company applied to Cyclotron Road, an entrepreneurial fellowship program that provides two years of funding as well as access to research labs, mentors, and a network of investors and experts. The program proved valuable, allowing the founders to nurture their budding technology and bring it out of the laboratory. It also gave them time to learn how to become entrepreneurs, Deka says.

During the fellowship, which ended in July, the company received a grant from the U.S. National Science Foundation. Deka and Labanowski are now getting the company off the ground and hiring their first employees.

Sonera Magnetics recently became a partner on a U.S. Air Force Research Laboratory project that aims to use neurotechnology to help pilots train and acquire new skills more quickly. Sonera’s role is to develop a brain-machine interface that combines the speed of EEG with the higher spatial resolution of MEG. Researchers could use the interface to gather data on brain activity when a human subject is in the process of learning.

IEEE COMMUNITY SUPPORT

The path from engineer to entrepreneur wasn’t an easy one, but Deka has taken it in stride. She recently was a panelist at an IEEE Entrepreneurship webinar, “New Tools, New Devices, New Fabs: Three Change-makers and Three Pathways in One Burgeoning Innovation Ecosystem,” in which she spoke about her experiences launching a microelectronics company.

IEEE, which she joined as an undergraduate student, has been a great community to stay connected with, she says. She joined the organization to stay up to date on emerging trends in the electronics field, but now she’s “diving into the entrepreneurship side,” she says.

“I’m learning more about the entrepreneurship work going on in the IEEE community,” she says. “We are doing a lot of scientific work in microelectronics at Sonera, and the IEEE is a good way to stay connected with others who are doing similar work.”

IEEE membership offers a wide range of benefits and opportunities for those who share a common interest in technology. If you are not already a member, consider joining IEEE and becoming part of a worldwide network of more than 400,000 students and professionals.

This article originally appeared in IEEE Spectrum on 09 December 2020.