@article {837336, title = {Multifunctional Actuation Systems Responding to Chemical Gradients}, journal = {Soft Matter}, volume = {8}, year = {2012}, note = {We thank Dr P. Kim, Dr U. Salman, and Dr A. Grinthal for discussions and Dr A. Taylor and Dr M. Khan for substrate fabri- cation. This work was supported by the DOE under award DE- SC0005247. L. D. Z. thanks the DoD for support through the NDSEG Fellowship Program as well as the NSF for support through the Graduate Research Fellowship Program}, pages = {8289-8293}, doi = {10.1039/C2SM26064F}, author = {L. D. Zarzar and Liu, Q. and He, X. and Hu, Y. and Suo, Z. and Aizenberg, J.} }