Associate Professor
School of Civil and Environmental Engineering

Since coming to Cornell from the University of Pittsburgh, where he chaired the Department of Civil and Environmental Engineering, Christopher Earls has reinvented his research program in keeping with his group’s unofficial motto “any structure, any size.”

That includes structures as large as steel bridges and as small as oscillators just 250 nanometers across. “The same laws of physics provide insight into the structural response across the 11 orders of magnitude that my research currently spans” he says. “A structure is a structure—it’s fascinating.”

Electronanomechanical oscillators are tiny diving-board-like structures that can be made to bounce up and down. Earls is working with Rob Ilic at the Cornell NanoScale Science and Technology Facility to find new ways of moving these tiny diving boards around. These new movements may lead to ways to shake off bound biological agents and reset the oscillator when it is used as a biosensor. Earls says that “it’s always interesting to see what applications people come up with once you figure out how to do something.” 

As he did in Pittsburgh, Earls still uses supercomputers to model the behavior of steel structures, but instead of looking at what happens to a building in the minutes during and after an earthquake, he’s now trying to find out what happens to a bridge in the milliseconds and seconds during and after an explosion. Since September 11, 2001, engineers have started considering how to design bridges to withstand bomb blasts, but they have very little data to work with. “It’s a poorly understood problem, and better tools are needed,” says Earls.

The same kind of sophisticated modeling, when applied to a ship, can give brains to the “idiot lights” that start blinking when there’s a problem. Right now, for example, the skippers of fast coastal vessels are told to slow down when a red light indicates excessive vibration, but such vibration can have several causes, not all of which warrant slowing down. Starting with the problem and the other known variables, the model can be used in reverse to pinpoint the likely cause of the vibration, letting the captain know if throttling back is really necessary.  

Earls has also reinvented his teaching style since coming to Cornell. In the two graduate courses he has taught so far and the undergraduate Introduction to the Behavior of Steel Structures, he is striving for less structure (no pun intended) and more improvisation. “Sometimes I’ll come to class and say, ‘You know what, let’s go into the lab this week and see how this stuff works.’”