MIT is known for mashing up disciplines, and Karl Berggren is a one-man illustration. His PhD is in physics—yet he’s an associate professor of electrical engineering who heads the Quantum Nanostructures and Nanofabrication Group, directs the Nanostructures Laboratory in the Research Laboratory of Electronics (RLE), and is a core faculty member in the Microsystems Technology Laboratories (MTL).
The denizens of Berggren’s laboratory—undergraduates and graduate students, post docs, faculty, even scientists from industry—are trained in electrical engineering, mechanical engineering, materials science, physics, and chemistry. They collaborate on the nanofabrication of structures, some only one ten-thousandth of the diameter of a human hair, that can be applied to superconductive quantum circuits, photodetectors, and energy systems.
Berggren spoke with MIT SPECTRVM about the benefits of intellectual diversity and where his exciting work may lead.
How does a physicist become a professor of electrical engineering (EE)?
After I got my PhD, I spent six years as a staff member at MIT’s Lincoln Laboratory. I got an incredible education there from my EE colleagues at the lab. Both my PhD work and my work at Lincoln was highly EE oriented, so the fit was pretty natural. In some ways huge swaths of the School of Engineering could reasonably be characterized as applied physics.
Tell us about the students in your lab, and how you work across so many disciplines.
When taking on new students, I often look for people whose backgrounds don’t overlap too much with the rest of the group. This broadens our range of skills, and forces everyone to use a simpler common language when talking with each other. The goal is to encourage fundamental work instead of work that is too narrow or overspecialized.
Can you tell us about a current research project in the Quantum Nanostructures and Nanofabrication Group?
We have been trying to find ways to lower the cost of the nanometer-length-scale pattern-formation process that is an essential part of integrated circuit manufacturing. We have been working closely with Caroline Ross and Alfredo Alexander-Katz, both materials science faculty, to combine nanometer-length-scale posts attached to a substrate with a special polymer. These posts can self-assemble when annealed—heated and then slowly cooled to strengthen—in order to form nanometer-scale spheres and cylinders. The posts are made using electronic beam lithography, which guides the self-assembly during the annealing phase.
Originally this work started as just a neat way to move around nanometer-scale structures, but now the whole integrated-circuit industry is looking to systems like this to lower their manufacturing costs and enable continued cost-effective device scaling.
We have entered the nano age. How do you think nanotechnology will have changed our world 20 years from now?
What we’re seeing now is the culmination of many years of work, starting perhaps 80 years ago, with the development of the electron microscope, and then accelerating in the late 1950s due to the efforts of people like Professor Dudley A. Buck and the legendary physicist Richard Feynman as well as the many pioneers of the integrated-circuit industry in the late 1950s.
Now these tools and techniques are readily accessible to large companies, universities, and researchers. Over the next century, I expect we’ll see these tools and methods become readily and cheaply available to smaller organizations and even individuals. Who knows what they might do with it?
I think we’re also going to see very different modalities of information processing emerge: materials and medicines that can do sophisticated information-processing tasks. It might become possible for so-called “smart” materials to do very sophisticated sensing, computation, and re-organization. I’d be very excited to see materials that can sense their environment and reconfigure or otherwise adjust their properties based on what they sense, and I don’t think it’s impossible.