The latest examples of microelectromechanical systems or MEMS were on display this past week at a conference in Las Vegas. Co-sponsored by the Institute of Electrical and Electronics Engineers and the Robotics and Automation Society, MEMS 2002 delved into the latest research on devices ranging from a small computer chip down to a few molecules in size. Scientists expect the technology to provide breakthroughs in several areas, including medicine, computers and robotics in the next few years.
Yogesh Gianchandani, a professor of electrical and computer engineer at both the University of Wisconsin and the University of Michigan, co-chaired the conference and served on its technical program committee. The IEEE had good reason to put him at the forefront of the meeting, since the MEMS industry has consulted him several times on how to design and build such devices.
The National Science Foundation awarded Gianchandani its Career Award in 2000, based on more than 15 years' work in integrated circuit design and fabrication. His research has looked at how microscopic sensors, mechanical components and integrated systems can fit into a wide range of applications.
He worked with Xerox and Microchip Technology before becoming a research fellow at the University of Michigan, and has published more than 50 papers concerning chipmaking and MEMS. He sat down with United Press International on the last day of MEMS '02 to discuss the conference's results.
Q. Congratulations are in order for a successful conference. From the statistics, it's obvious interest in the field is certainly growing rapidly.
A. Thanks. If you include the people who walked in over the past couple of days, we have about 700 registered attendees ... which is a very substantial record for the conference, and since it's in a negative (economic) year we're very, very gratified.
Q. At some point it becomes difficult to differentiate between MEMS, which is more at the micron (millionths of an inch) scale, and nanotechnology, when you're getting down to nanometers (billionths of an inch) or even Angstroms. What would you say is a good general-purpose dividing line between the two, or is there one?
A. I don't know if there is one. I guess you could pick a dividing line of dimension, since nanotechnology is a few orders of magnitude smaller, but I like to look at it somewhat differently. MEMS technology is still linked to chip manufacturing technology. (Process) limits allow this to go down to about a tenth of a micron, so down to that dimension we can still use the batch manufacturing techniques that are used for integrated circuits. With nanotechnology you need some other approaches, and that might be one way to distinguish between them, and that might be a more meaningful distinction than dimension.
Q. In the conference's first presentation, we heard about a nanoscale motor based on biological molecules. When we start talking about using protein molecules for motors, then we're down into the tens of nanometers; that would seem to indicate another step of technology necessary to do that on a more meaningful scale than simply assembling things in the lab.
A. There are many important constraints that remain to be fulfilled. They're trying to create arrays of those things now. When you get that small, you have to have a technology that will allow you to locate these motors at the positions you want them. You have to have testing techniques to ensure they're working, calibration techniques. (Researchers) have also mentioned that, at this point, these motors are only working in liquids, so it's going to be a significant challenge to power these things, since the liquid serves as the fuel transportation medium. We're some years away from seeing that particular device, but it's hard to predict the future. I don't want to be in that business, because some clever person might find a niche application for it, and might find a way to accommodate it into existing fabrication techniques.
Q. Many of the presentations here, both oral and in the poster sessions, have focused on individual devices as opposed to an overall system. There was an "electronic fountain pen," which seemed to be a fully integrated system, but what kind of conclusions can be drawn from the fact that a lot of the presentations seem to be at the discrete device stage as opposed to more of an integrated system?
A. In order to develop a system, you typically develop the individual devices first. You may also have a system that incorporates three existing blocks and one new block, then the paper would and should focus on the new block, and I think you're seeing an artifact of that. You're seeing the fact that these are the first things people have to attack, because these devices are the first aspect of research people focus on; it's the biggest unknown.
Q. This year, we've seen a couple of presentations on more complete systems. Is it reasonable to think that once MEMS 03 rolls around, we'll see even more presentations on full systems? Are we to the point where the problems dealing with the individual devices are being solved, and we can move on to systems integration?
A. That's happening on a continuous basis; we don't have to wait for MEMS 03 to do that. The question is, will it get reported? And if it's reported, will the challenges that were addressed in systems integration be suitable for presentation at this conference, from the point of interest for our attendees? For example, hypothetically, there may be a closed-loop system that has a conventional control scheme that uses a new kind of sensor and new kind of actuator. We'd like to hear about the sensor and actuator, and there may be people here who'll benefit from hearing about the control system, but that will be up to the technical program committee to make that decision.
Q. There have been a number of very interesting papers, but from a technical standpoint, what presentations particularly caught your eye?
A. I wouldn't pick out a single presentation, but I have to tell you this: We have a very low acceptance rate for this conference. Each year, we find the quality of the submissions gets better and better, the standard keeps rising as we see the field maturing. It's so obvious as you see the papers year after year, and I think the attendees know it. Everything that you see here has been through the wringer, so I wouldn't single one out.
Q. Is there anything else about the conference or the technology we should mention?
A. Given what we've seen at this conference, we should expect commercial interest to continue to grow, as more of these devices come out of the research labs and into production. We hope that will continue.