Sterling McBride: Three decades of quantum innovation

SRI’s Sterling McBride, principal quantum research scientist

McBride’s path to creating best-in-class quantum sensors started over 30 years ago at SRI, in microfluidics.

My PhD is in electrical engineering from the University of Texas at Dallas (UTD) and my journey to SRI began there. My professor and I would attend meetings of the American Physical Society, where, in 1993 I was recruited to work at the David Sarnoff Research Center, now part of SRI. I was interested in the work, especially after I learned more about SRI and how its history was a big part of the early technical revolution, akin to storied places like Bell Labs, the Palo Alto Research Center, and the Hughes Research Laboratories.

My initial work at SRI involved solving problems that had to do with iris recognition and improving illumination to capture insights into the iris. At that time there was new interest from pharmaceutical companies to create a lab-on-a-chip, a process to enable the efficient handling of small volumes of fluids in microchannels smaller than a strand of hair. These ideas would soon result in a microfluidic platform that integrates various lab operations such as biochemical analysis, chemical synthesis, and DNA sequencing.

Developing quantum sensors

Roughly three months into my new job, I got the chance to join a team doing initial experiments that would transport fluids using electric fields inside microchannels. I continued my work on microfluidic projects for many years, and our team grew to 50 people, taking up an entire floor of our building in Princeton, New Jersey.

“The devices we’re making are among the best in the world, and I consider my quantum work the pinnacle of my life’s experience – my work at SRI has resulted in more than 50 issued US patents,” said McBride.

Today, I’m a principal research scientist for SRI’s Quantum and Semiconductors Laboratory, focused on developing quantum sensors. Quantum sensors can detect electromagnetic fields, keep accurate timing, perform inertial measurements, and will be used to improve position navigation and timing (PNT) systems, RF receivers and antennas, medical imaging systems, geological and mineral exploration, and environmental monitoring.

My work on quantum sensors started with the DARPA CSAC program to develop a miniature atomic clock that is about the size of a sugar cube. I’m most proud of pioneering the microfabricated structures used in quantum sensors, and microfabrication technologies derived from the microfluidics work.

Quantum sensors can lead to medical breakthroughs

One of these sensors is a highly sensitive magnetometer and can measure very small magnetic fields produced by the firing of the neuron in the human brain. These types of sensors have tremendous implications for improved medical diagnosis and brain function understanding. Additional sensors include a new paradigm in radiofrequency receivers where Rydberg atoms in microfabricated structures are used to detect electromagnetic fields.

Microfabricated structures, including integrated photonics, are being used to develop highly sensitive gyroscopes that will surpass today’s PNT performance. Miniaturizing sensors is the culmination of more than 20 years of experience to perfect them from simple devices to very small complex ones.

Collaboration, diversity, and impact

The devices we’re making now are among the best in the world, and I consider my quantum work the pinnacle of my life’s experience – my work at SRI has resulted in more than 50 issued US patents.

Working here is very collaborative across multidisciplinary teams – physics, electronics, microfabrication, software, and more. We also work across academia, industry, and government. At SRI, we’re always creating something new and disruptive. I feel like I’ve completed several PhDs by now, and our lab, as well as the whole of SRI, has delivered impactful systems and platforms that make a big difference in people’s lives.

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