Ruonan Han looks for to press the limitations of electronic circuits.
Ruonan Han’s research study is increasing the speeds of microelectronic circuits to make it possible for brand-new applications in interactions, noticing, and security.
Han, an associate teacher who just recently made tenured in MIT‘s Department of Electrical Engineering and Computer Science, concentrates on producing semiconductors that run effectively at extremely high frequencies in an effort to bridge what is referred to as the “terahertz gap.”
The terahertz area of the electro-magnetic spectrum, which lies in between microwaves and infrared light, has actually mainly avoided scientists due to the fact that standard electronic gadgets are too sluggish to control terahertz waves.
Ruonan Han, associate teacher in the Department of Electrical Engineering and Computer Science, looks for to press the limitations of electronic gadgets so they can run effectively at terahertz frequencies. Credit: M. Scott Brauer
“Traditionally, terahertz has been unexplored territory for researchers simply because, frequency-wise, it is too high for the electronics people and too low for the photonics people,” he states. “We have a lot of limitations in the materials and speeds of devices that can reach those frequencies, but once you get there, a lot of amazing things happen.”
For circumstances, terahertz frequency waves can move through strong surface areas and produce extremely accurate, high-resolution pictures of what is within, Han states.
Radio frequency (RF) waves can take a trip through surface areas, too– that’s the factor your Wi-Fi router can be in a various space than your computer system. But terahertz waves are much smaller sized than radio waves, so the gadgets that transfer and get them can be smaller sized, too.
Han’s group, in addition to his partner Anantha Chandrakasan, dean of the School of Engineering and the Vannevar Bush Professor of Electrical Engineering and Computer Science, just recently showed a terahertz frequency recognition (TFID) tag that was hardly 1 square millimeter in size.
“It doesn’t need to have any external antennas, so it is essentially just a piece of silicon that is super-cheap, super-small, and can still deliver the functions that a normal RFID tag can do. Because it is so small, you could now tag pretty much any product you want and track logistics information such as the history of manufacturing, etc. We couldn’t do this before, but now it becomes a possibility,” he states.
Tuning in
An easy radio influenced Han to pursue engineering.
As a kid in Inner Mongolia, a province that extends along China’s northern border, he read books filled with circuit schematics and diy ideas for making printed circuit boards. The main school trainee then taught himself to construct a radio.
“I couldn’t invest a lot into those electronic components or spend too much time tinkering with them, but that was where the seed was planted,” he states. “I didn’t know all the details of how it worked, but when I turned it on and saw all the components working together it was really amazing.”
Han is pleased he’s at MIT, where the trainees aren’t scared to handle apparently intractable issues and he can work together with associates who are doing unbelievable research study in their domains. Credit: M. Scott Brauer
Han studied microelectronics at Fudan University in Shanghai, concentrating on semiconductor physics, circuit style, and microfabrication.
Rapid advances from Silicon Valley tech business influenced Han to enlist in a U.S. graduate school. While making his master’s degree at the University of Florida, he operated in the laboratory of Kenneth O, a leader of the terahertz incorporated circuits that now drive Han’s research study.
“Back then, terahertz was considered to be ‘too high’ for silicon chips, so a lot of people thought it was a crazy idea. But not me. I felt really fortunate to be able to work with him,” Han states.
He continued this research study as a PhD trainee at Cornell University, where he refined ingenious strategies to turbo charge the power that silicon chips can produce in the terahertz domain.
“With my Cornell advisor, Ehsan Afshari, we experimented with different types of silicon chips and innovated many mathematics and physics ‘hacks’ to make them run at very high frequencies,” he states.
As the chips lessened and quicker, Han pressed them to their limitations.
Making terahertz available
Han brought that ingenious spirit to MIT when he signed up with the EECS professors as an assistant teacher in2014 He was still pressing the efficiency limitations of silicon chips, now with an eye on useful applications.
“Our goal is not only to work on the electronics, but to explore the applications that these electronics can enable, and demonstrate the feasibility of those applications. One especially important aspect of my research is that we don’t just want to deal with the terahertz spectrum, we want to make it accessible. We don’t want this to just happen inside labs, but to be used by everybody. So, you need to have very low-cost, very reliable components to be able to deliver those kinds of capabilities,” he states.
Han is studying using the terahertz band for fast, high-volume information transfer that might press cordless gadgets beyond 5G. The terahertz band might be helpful for wired interactions, too. Han just recently showed using ultrathin cable televisions to transfer information in between 2 points at a speed of 100 gigabits per second.
Terahertz waves likewise have special homes beyond their applications in interactions gadgets. The waves trigger various particles to turn at special speeds, so scientists can utilize terahertz gadgets to expose the structure of a compound.
“We can actually make low-cost silicon chips that can ‘smell’ a gas. We’ve created a spectrometer that can simultaneously identify a large range of gas molecules with very low false alarms and high sensitivity. This is something that the other spectrum is not good at,” he states.
Han’s group made use of this work to create a molecular clock that turns the molecular rotation rate into an extremely steady electrical timing signal for navigation, interaction, and noticing systems. Although it operates just like an atomic clock, this silicon chip has an easier structure and considerably minimized expense and size.
Operating in mainly undiscovered locations makes this work specifically difficult, Han states. Despite years of advances, semiconductor electronic devices still aren’t quickly enough, so Han and his trainees need to continuously innovate to reach the level of performance needed for terahertz gadgets.
The work likewise needs an interdisciplinary state of mind. Collaborating with associates in other domains, such as chemistry and physics, makes it possible for Han to check out how the innovation can cause helpful brand-new applications.
Han is pleased he’s at MIT, where the trainees aren’t scared to handle apparently intractable issues and he can work together with associates who are doing unbelievable research study in their domains.
“Every day we are facing new problems and thinking about ideas that other people, even people who work in this field, may consider super-crazy. And this field is in its infancy right now. There are a lot of new emerging materials and components, and new needs and potential applications keep popping up. This is just the beginning. There are going to be very big opportunities lying ahead of us,” he states.
