Contact Information:
e-mail:
phone: (217) 244-4973
212a Ceramic Building
MC-246,
105 South Goodwin
Urbana, IL 61801
The principal activities of the Lewis Group involve the directed and self assembly of materials comprised of colloidal, nanoparticle, and polyelectrolyte building blocks. Our efforts are aimed at establishing fundamental knowledge of the phase behavior, structure, rheology, and assembly of complex fluids. We are developing broad expertise in probing such interactions via light scattering, rheological techniques, in situ drying stress measurements, and direct visualization techniques, such as confocal microscopy and high speed imaging.
We have studied the phase behavior of a broad range of complex fluids, including colloid mixtures, colloid-polymer mixtures, colloid-filled hydrogels, and reactive colloid systems. Our approach relies on establishing the structure of, and transitions between the fluid, gel, crystalline and glassy states as a function of varying composition, size, and interparticle interaction strength. With this knowledge, we can design novel systems for fabricating functional ceramics, photonic band gap materials, catalyst supports, and scaffolds for biological self assembly.
Our efforts in direct-write assembly focus on creating complex, 3-D structures of locally tailored structure and composition at the mesoscale (~ 0.5 µm to 1 mm). New areas of interest include self patterning films and microfluidic-directed assembly of materials.
X. Guo, H. Li, B.Y. Ahn, E.B. Duoss, K.J. Hsia, J.A. Lewis, and R.G. Nuzzo, "Two and Three-Dimensional Folding of Thin Film Single-Crystalline Silicon for Photovoltaic Power Applications," Proceedings of the National Academy of Science (in press). (cover article)
B.Y. Ahn, E.B. Duoss, M.J. Motala, X. Guo, S.-I. Park, Y. Xiong, J. Yoon, J. Yoon, R.G. Nuzzo, J.A. Rogers, and J.A. Lewis, "Omnidirectional Printing of Flexible, Spanning, and Stretchable Silver Microelectrodes," Science, 323, 1590-93 (2009).
M.C. George, A. Mohraz, M. Piech, N.S. Bell, J.A. Lewis, and P.V. Braun, "Direct Laser Writing of Photoresponsive Colloids for Microscale Patterning of 3D Porous Structures," Advanced Materials, 21, 66-70 (2009). (cover article)
S.K. Rhodes, R.H. Lambeth, J. Gonzales, J.S. Moore, and J.A. Lewis,, "Cationic Comb Polymer Superdispersants for Colloidal Silica Suspensions," Langmuir, 25, 6787-92 (2009). [DOI:10.102/la9003092]
R.A. Barry, R.F. Shepherd, J.N. Hanson, R.G. Nuzzo, P. Wiltzius, and J.A. Lewis, "Direct-Write Assembly of 3D Hydrogel Scaffolds for Guided Cell Growth," Advanced Materials, 1-4 (2009).
