We fabricate polymeric photonic crystals using self-assembly, especially with block copolymers, and by holographic interference lithography. Emphasis is placed on the understanding of complex relations between the lattice symmetry and optical properties of periodic structures.

For example, a self-assembling gel consisting of alternating layers of two polymers, hydrophobic polystyrene and hydrophilic poly-2-vinyl-pyridine (P2VP) can rapidly change color in response to a range of stmuli, including temperature, humidity, and salt concentration. The photonic gel could lead to a variety of applications including sensors and display devices.

Relevant Paperworks:

Noro, A., Tomita, Y., Shinohara, Y., Sageshima, Y., Walish, J.J,, Matsushita, Y., Thomas, E.L., “Photonic Block Copolymer Films Swollen with an Ionic Liquid”, Macromolecules, 47(12),4103–4109 (2014)

Lim, H.S., Lee, J.-H., Walish, J.J., Thomas, Edwin, “Dynamic Swelling of Tunable Full-Color Block Copolymer Photonic Gels via Counterion Exchange,” ACS Nano, 6, 8933 (2012)