MEMS Research Alert: Ultra-low-dissipation Micromechanical SiC Resonators with Q > 18 Million
Dr. Hamelin, Jeremy Yang, and co-workers in the iMEMS Lab, under the supervision of Professor Farrokh Ayazi, Ken Byers Professor in Microsystems in the School of Electrical and Computer Engineering, and with technical assistance from IEN, have demonstrated mechanical quality factors (Q) beyond 18M in millimeter-size SiC disk resonators anchored upon self-aligned pedestals on acoustically-engineered Si substrates. By reducing undesired coupling to its environment, ultra-high Q resonators exhibit both low mechanical noise and high sensitivity while being solidly anchored on a phononic crystal silicon substrate. While monocrystalline Si is the standard substrate for MEMS fabrication, its theoretical ƒ·Q product is 30X below the limit of monocrystalline SiC, limiting its intrinsic Q factor. Although SiC has been investigated as a MEMS material in the past, researchers were mostly limited to deposited thin polycrystalline films with high intrinsic losses and limited application. Micromachining of monocrystalline 4H SiC MEMS with superior material properties in wafer form has remained an unchartered territory, owing to the lack of precision high-aspect-ratio plasma etching of SiC. By overcoming these hurdles, researchers at the iMEMS Lab have demonstrated capacitive SiC disk resonators with ƒ·Q=9·1013Hz, up to 4-fold above the quantum Akhiezer limit of Si. Through further improvements in the fabrication process, Qs beyond 100M at 1MHz and at room temperature are theoretically within reach. These experimental results, published in Scientific Reports, present a major stepping-stone towards the deployment of high-precision MEMS instruments, including gyroscopes for pedestrian navigation in GPS-occluded environments.
Image Description: SEM view of a 40µm-thick monocrystalline 4H SiC disk resonator with integrated capacitive transducers, showing mechanical Q factor of 18Million, beyond the limits of Si. The electrodes (colored in yellow) are coated with polycrystalline silicon to facilitate electrical measurements.
IEN Staff Member, & Ph.D. Candidate, Devin Brown Wins Best Student Poster Presentation at the 2019 International Conference on Electron, Ion, and Photon Beam Technology and Nanofabrication (EIPBN)
Congratulations to IEN Staff Specialist in E-Beam Lithography, and ECE Ph.D. Candidate, Devin Brown for his win at EIPBN 2019! Devin balances his full-time position as IEN staff with his Ph.D. topic research work, producing top-notch results in both.
The title of Brown’s award-winning poster is “Nanoscale Metallic Resistors in Soft Polymers.” His coauthors on the poster are ECE Professor and IEN Executive Director Oliver Brand, who serves as Brown’s advisor, and Mingu Kim, a recent Ph.D. graduate of Brand’s research group who is now a postdoctoral fellow at Stanford University. The work is the result of a collaboration with Associate Professor Wilbur Lam and Assistant Professor David Myers, both of the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University.
A view of the presentation is available here: https://www.youtube.com/watch?v=NY7BgZGfSWA&feature=youtu.be
Azadeh Ansari Receives NSF CAREER Award
National Science Foundation CAREER Award. Ansari holds the Sutterfield Family Junior Professorship in the Georgia Tech School of Electrical and Computer Engineering (ECE).
The title of her award is "Radio Frequency Spectrum Sensing with a Fine-Tooth Nanomechanical Comb,” and it will start on March 1, 2020 and end on February 28, 2025. The tremendous growth of wireless devices and Internet of Things (IoT) applications has placed a great strain on the radio frequency (RF) network infrastructures, congesting the channels and overcrowding the radio frequency spectrum.
Ansari has published over 30 refereed journal and conference papers and has one published patent and three patent applications. She was a Center for Teaching and Learning Class of 1969 teaching fellow in Spring 2019. Ansari is the director of the Center for Muscle-Inspired Actuators for Multi-scale Robotics, an Institute for Electronics and Nanotechnology-funded center for multi-disciplinary research.
Dupuis Wins Materials Today Innovation Award
Russell D. Dupuis has been honored with the Materials Today Innovation Award. He was presented with the award at the 2019 Materials Research Society Fall Meeting and Exhibit, held December 1-6 in Boston, Massachusetts. Dupuis holds the Steve W. Chaddick Endowed Chair in Electro-Optics and is a Georgia Research Alliance Eminent Scholar in the Georgia Tech School of Electrical and Computer Engineering (ECE).
Dupuis was specifically recognized “for pioneering development of the metalorganic chemical vapor deposition (MOCVD) technology and seminal contributions to compound semiconductor materials and devices, including the first MOCVD III-V compound semiconductor solar cells, and advances in quantum-well semiconductor light emitters used in telecommunications and visible LEDs (light-emitting diodes).”
February 25 - Lisa Yaszek, School of Literature, Media, and Communications, Georgia Tech
March 10 - Debra Rolison, Naval Research Laboratory (Invited by Graduates in Nanotechnology)
March 24 - David Myers, Wallace H. Coulter Department of Biomedical Engineering, Georgia Tech
April 14 - Khalid Salaita, Department of Chemistry, Emory Univ.
April 28 - Hitesh Handa, School of Chemical, Materials, and Biomedical Engineering, Univ. of Georgia
Packaging Research Center Distinguished Lecture Series : Rubbery Electronics - Towards a Seamless Integration with Humans
Cunjiang Yu, Ph.D. - Bill D. Cook Professor of Mechanical Engineering, University of Houston
Abstract: Seamlessly merging electronics with biology is of imminent importance in addressing grand societal challenges in health and joy of living. However, the main challenge lies in the huge mechanical mismatch between the current form of rigid electronics and the soft curvy nature of biology. In this talk, I will present a new type of electronics, namely “rubbery electronics”, with tissue-like softness and stretchability, which is constructed all based on elastic rubbery electronic materials. The hope is that rubbery electronics could ultimately solve the challenge in seamless integration between biology and electronics. The rubbery electronic materials and device innovations set a foundation for rubbery electronics. Fully rubbery transistors, logic gates, integrated electronics, sensors, smart skins, medical implants, and neurologically integrated function systems will be demonstrated.
Bio: Dr. Cunjiang Yu is the Bill D. Cook Associate Professor of Mechanical Engineering at the University of Houston, with joint appointments in Electrical and Computer Engineering, Biomedical Engineering, and Materials Science and Engineering. He completed his Ph.D. in Mechanical Engineering at Arizona State University in 2010 and was trained as a postdoc at the University of Illinois at Urbana-Champaign before joining the University of Houston in 2013. Dr. Yu is a recipient of NSF CAREER Award, ONR Young Investigator Award, MIT Technology Review Top Innovators, SME Outstanding Young Manufacturing Engineer Award, AVS Young Investigator Award, ACS Petroleum Research Fund Doctoral New Investigator Award, and the 3M Non-Tenured Faculty Award.
Nanovation Podcast hosted by Prof. Michael Filler: Is our technology future paved with complex oxides? - with guest Nazanin Bassiri-Gharb
Nazanin Bassiri-Gharb, a Professor of Mechanical Engineering at Georgia Tech, joins Mike to talk about complex oxides. Complex oxides are multi-component materials that yield a bevy of exotic properties. Much of the podcast centers on ferroelectricity, the ability of certain materials to exhibit an internal polarization that can be switched with an external electric field. Nazanin and Mike talk about the current use of ferroelectrics in technologies from ultrasound imaging to data storage, as well as their potential future use in brain-like or neuromorphic computers. Throughout the episode, Nazanin's love of and excitement for science and engineering shines through. Be careful, it's infectious! (Recorded on Nov. 14, 2019. Edited by Andrew Cannon)
“The Committees for North America, Asia, and Europe for the International Meeting on Chemical Sensors” invite you to IMCS 2020, to be held in Montreal during May 2020. This will be the 18th in a series of successful meetings for researchers, professionals, and business leaders to see the state of the art in sensors for gases, liquids, biologicals, for applications in health and environment, wearables and fixed infrastructure, as well as wired and wireless.