Englund Group, Columbia University (summer 2011-present): My current research project involves the development of micrometer-scale PMMA gas sensors that have potential applications in medicine and industry. The sensors are Bragg reflectors that alternates air and PMMA to create a two dimensional photonic crystal (a material that affects photons in a similar way that semiconductors affect electrons). When the device absorbs a gas that is soluble in the PMMA polymer, the properties of the photonic crystal are affected and the shift in the wavelength of the emitted light is detectable.