Faculty Spotlights

Srinivas Tadigadapa

Srinivas Tadigadap

Professor Srinivas Tadigadapa (Electrical Engineering) arrived at Penn State a little over two years ago, but has rapidly made connections with faculty all over campus. One of the reasons he cites for coming to Penn State was the large number of faculty involved in materials. Virtually all of his research involves microelectromechanical systems (MEMS). His specific expertise is in the design and fabrication of MEMS and thus views faculty that are working with exciting new materials as potential collaborators.

Piezoelectrically drive MEMS RF Switch
movement of the cantileve switch with actuation voltage
Image of switching characteristics
A piezoelectrically driven MEMS RF Switch. SEM photographs show the movement of the cantilever switch with actuation voltage and the switching characteristics.

Currently, he is working with Susan Trolier-McKinstry (Materials Science & Engineering) and Thomas Jackson (Electrical Engineering) to fabricate piezoelectric-based RF switches which offer distinct advantages in speed and linearity over conventional RF switches. He has completed a project on piezoelectric accelerometers for industrial applications. He is also working with Peter Eklund (Physics) on using MEMS techniques to make electrical measurements on carbon nanowires, a difficult feat based on the scale difference between what can be fabricated using traditional and electron beam lithography and the size of the nanowires. He has funding through the MRSEC with Moses Chan (Physics) to fabricate microcavities for capacitively measuring critical Casimir forces in confined 3He fluids. Perhaps the research that he is most excited about is a collaboration with Andy Ewing (Chemistry) that is funded by a seed grant from the Huck Institute for Life Sciences. His group is attempting to fabricate a 2-dimensional array of quartz crystal oscillators for detecting femtogram quantities of chemicals that are released during neural communication. Their hope is to be able to deposit cells across an array then stimulate them and watch the response as the resonance frequency of these tiny oscillators is shifted by individual molecular adsorption events. In the process of fabricating these devices his group has developed an elegant way of bonding complex MEMS devices together to form the microchannels needed to deliver chemicals to the array. Their method involves depositing a thin, continuous line of metal around the device then electroplating several microns of tin on top. Two devices with matching features can be mated. A small amount of heat applied melts the tin making an incredibly strong, hermetic seal. His hope is that this approach will become another standard fabrication method for the MEMS community.

d33-piezoelectric MEMS accelerometer
accelerometer frequency response
A d33-piezoelectric MEMS accelerometer and its frequency response.