Glass-Based Fexible Integrated Photonic Devices

Conventional integrated photonic devices are fabricated almost exclusively on rigid substrates such as silicon wafers. The proposed program aims to develop the fundamental optical physics and device processing know-how that enable photonic integration on unconventional flexible plastic substrates. By imparting mechanical flexibility to photonic structures, the research will advance understanding into optical and mechanical interaction mechanisms in the nanoscale, and open up emerging application venues including humanlike robotic skins, prosthetic limbs, minimally invasive surgical tools, and touch panels for flexible consumer electronics. The scientific research will be tightly integrated with curriculum development, undergraduate student training, and development of hands-on modules for optics education. Research outcome from the project will be incorporated into a new course on amorphous materials the PI will develop. In addition to augmenting classroom education at MIT, the program will also promote the free sharing and distribution of knowledge by developing online courses through the edX initiative. The participating undergraduate and graduate researchers will benefit from the interdisciplinary research as well as cross-cutting collaborations to extend their technical experiences. The program will also develop hands-on modules for K-12 students and the general public to promote public awareness of optical sciences and nanotechnology through working with the MIT Edgerton Center and local museums.

Flexible photonics is uniquely poised at the nexus between photonics, mechanics, and materials sciences. While previously the topic has largely been explored from the three isolated fields, the proposed research will pioneer an interdisciplinary approach synergistically combining innovative photonic design, nano-mechanical engineering, and unconventional material processing to unravel the rich physics underlying tensorial strain-optical interactions and apply the principle to multidirectional stress measurement. Glasses, the backbone materials for lenses and fibers, will be explored as the preferred optical materials for photonic integration onto unconventional plastic substrates exploiting their low optical losses and extreme processing versatility, as they can be monolithically deposited on virtually any technically important substrate and can be shaped into functional device forms via traditional lithography or soft lithographic methods including molding, imprint, and ink jet printing. Further, while traditional planar photonic circuits on flat substrates are 2-D in nature, the proposed research will utilize the additional geometric degrees of freedom conferred by mechanical flexibility to create a 3-D photonics platform based on planar microfabrication, a technology that will enable pinpointing light-matter interaction locations in a 3-D space inaccessible to conventional "flat" photonics and thus will have immense application potentials for sensing, communications, and imaging.