“I especially like people who can think outside the box”

Kyojin Choo has just been appointed tenure-track assistant professor at School of Engineering © Alain Herzog 2022 EPFL

Kyojin Choo has just been appointed tenure-track assistant professor at School of Engineering © Alain Herzog 2022 EPFL

Kyojin Choo has just been appointed tenure-track assistant professor at EPFL’s School of Engineering, where he will combine research in power management, microtechnology and analog-to-digital converters (ADC) to make electronics smaller and more efficient. 

ADCs are electronic circuits used to transform analogue signals, such as sound or light, into binary ones. This technology is used in everyday devices such as smartphones and cameras. Choo has been developing methods to improve ADCs, and will now take his work further through his new role as EPFL professor and head of the Mixed-Signal Integrated Circuits Lab at the Institute of Electrical and Micro Engineering. He’s based at the Microcity campus in Neuchâtel.

Potter, clarinetist and circuit designer

A potter and clarinetist in his free time, 37-year-old Choo first worked in industry and spent four years at Samsung Electronics designing circuits for CMOS image sensors. He went on to complete his PhD and postdoctoral studies at the University of Michigan where he developed several methods for low-power circuits.

Choo now wants to create smaller, more efficient ADCs in line with the next generation of even smaller (and sometimes barely perceptible) devices. "Size matters because it dictates the shape and cost of most consumer electronics. If we make ADCs smaller, we pack more into each device and boost its performance or we could reduce the amount of material required to make it," he says. "The goal is to use smaller ADCs in implants and as parts for precision mechanics, like for watches." Choo aims to design systems that will be thinner than a coin. However, the batteries for such devices is still a challenge – electronics must be extremely energy-efficient for it to last long enough for regular use, even in a miniaturized state.

Opening new doors

The new professor is also preparing, albeit apprehensively, to teach his first class to Master’s students. "Teaching will be a real challenge because here are so many great teachers that raises the bar, but I enjoy connecting with students. It’s interesting for me to dig into their logic and reasoning." Choo is looking for motivated PhD students to join his lab, and already has a clear idea of what he expects from them. "These individuals must be able to think on their feet, since we almost always have to solve problems relatively quickly. I especially like people who can think outside the box. At EPFL, we’re lucky to have the freedom to let our imaginations run wild and experiment." He stresses the importance of getting at the heart of a problem. If you want things to run efficiently at a macro level, you’ve got to get the details right on a micro scale.