MSE PhD Final Defense of Thomas Stark

Title: MEMS for Tunable Photonic Metamaterial Applications

Abstract: Photonic metamaterials are materials whose optical properties are derived from artificially structured sub-wavelength unit cells, rather than from the bulk properties of the constituent materials. Examples of metamaterials include plasmonic materials, negative index materials, and electromagnetic cloaks. MEMS based solutions to two main challenges in this field are presented: fabrication of photonic metamaterials with tunable responses and high-throughput nanofabrication methods for these materials.

A MEMS tunable plasmonic spectrometer, which consists of an array of holes in a suspended gold film coupled to a tunable length Fabry-Pérot interferometer, was developed. MEMS actuation enables dynamic tuning of the system’s response in the mid-infrared. Due to its broad spectral tunability in the fingerprint region of the mid-infrared, this device shows promise as a tunable organic sensing device.

To address the issue of high-throughput, high-resolution fabrication of photonic metamaterials, a MEMSbased dynamic stencil lithography technique for resist-free nanofabrication on unconventional substrates, has been developed. This “atomic calligraphy” system leverages the nanometer precision of MEMS actuation, while enhancing nanofabrication throughput over macroscopic length scales. The technique shows promise for fabrication on unconventional substrates, such as soft mechanical scaffolds, which can be strained to tune the electromagnetic response of photonic metamaterials.

Committee: Advisor: David J. Bishop, MSE/ECE/Physics; Soumendra N. Basu, MSE/ME; Shyamsunder Erramilli, MSE/Physics/BME; Anna Swann, MSE/ECE; Chair: Alice White, ME