Figure 2.

Functional materials and mechanisms composed from field‐responsive media leverage graded mechanical compliance, nonlinearity, multiple degrees of freedom, and cross‐filed coupling for versatility in function. a) Patterned gel sheets in the aqueous medium, undergoing 3D shape transformation in response to temperature change. Adapted with permission.^{[ 133 ]} Copyright 2012, American Association for the Advancement of Science. b) Octobot‐like robot, powered by combustion and controlled by microfluidic logic to alternate between two states. Adapted with permission.^{[ 148 ]} Copyright 2016, Springer Nature. c) Flexible electronic materials created from 3D printed conductive ink that is used to monitor joint bending. Adapted with permission.^{[ 149 ]} Copyright 2017, John Wiley & Sons, Inc.