EECS Ph.D. Student Won Best Student Paper Award at IEEE International Frequency Control Symposium

Jaesung LeeJaesung Lee, a Ph.D. student in the Department of Electrical Engineering & Computer Science (EECS), mentored by Prof. Philip Feng, has won a Best Student Paper Competition at the 2014 IEEE International Frequency Control Symposium (IEEE IFCS 2014), for presenting his paper entitled “Atomically-Thin MoS2 Resonators for Pressure Sensing”. 

In this paper, Jaesung Lee and Philip Feng reported an experimental investigation of a new type of nanoscale devices that are exceptionally responsive to small pressure variations and yet can tolerate pressure changes over wide ranges.  The devices are circular drumhead membranes suspended over microscale cavities patterned on a silicon chip.  These membranes are derived from molybdenum disulfide (MoS2), a layered semiconducting material, which can be transferred onto a substrate to make two-dimensional (2D) crystals as thin as just a single or a few atomic layers.  Not only do the researchers make such ultrathin structures, but also they make these 2D crystals free to move and vibrate.  They use focused laser beams to strike these atomically thin drumheads, and study their vibrations at very high tones.  They find the vibrations of these nanoscale drumhead resonators are highly sensitive to environment pressure variations, orders of magnitude more responsive than conventional, much bigger diaphragms for pressure sensing.  Because the 2D membranes are extremely flexible and do not suffer from brittleness, they can operate over a wide pressure range.  With further engineering, these devices and the optical techniques used can be integrated into flexible optical fibers, which may lead to ultrasensitive pressure monitoring in harsh environments such as inside human body and in drilling or mining downholes, where electrical wiring of sensors is often undesirable. 

In previously published research, Jaesung, Prof. Feng and their colleagues demonstrated the world’s first MoS2 2D nanoresonators, also featured by NanotechWeb and the Royal Society’s ChemistryWorld.  Upon winning this student paper competition, Jaesung said, “I am honored and very fortunate.  I have learned a lot from this conference and the IFCS community.  It’s a very encouraging news for me that people think our experiments on the new 2D devices are interesting.” 

IEEE IFCS is the annual international forum on frequency control, time standards, and sensing technologies, including a wide range of emerging devices such as MEMS and NEMS resonators, integrated electrical oscillators and clocks, microwave frequency standards, and chip-scale atomic clocks.  Each finalist of the paper competition was required to give both a poster presentation in front of a group of judges, and an podium oral presentation in a session.  Joining Jaesung on this paper is his advisor Prof. Philip Feng.  This work has been supported by Case School of Engineering and the National Academy of Engineering’s Grainger Foundation Frontiers of Engineering (FOE) Award.  Part of Jaesung’s travel support has been generously provided by the IEEE Ultrasonics, Ferroelectrics and Frequency Control (UFFC) Society for student paper competition finalists.