Dr. Lidong Zhang, Professor, Department of Chemistry and Molecular Engineering, East China Normal University, Shanghai, China

Title: Stimuli-responsive polymer composites with controllable kinematics

Abstract: Stimuli-responsiveness is a fundamental process of energy conversion that is essential for applications which require contactless actuation in response to environmental stimuli. Herein we demonstrate a series of polymer composite films that are capable of rapid shape change by a flexible dynamic element which harnesses external stimuli for motility.

These kinematic self-actuations are expected to utilize in controlled sensors or microscopic soft energy conversion devices; therefore, controllable kinematics are essential. We develop controllable kinematics through the manipulation of composite film actuators with interfacial chemical reactions, macroscopic surface patterns, and microscopic surface patterns. As a result, the actuators respond to external stimuli including humidity, sunlight, acetone vapors or others with controlled curling, bending, twisting, and rolling over a template. Such dynamic behaviors are combined with electronic devices capable of showing qualitative detection of environmental humidity and acetone vapors.

Moreover, stimuli-responsive features allow for conversion of water-responsive sodium alginate film into hollow hydrogel tube that can be further functionalized to achieve more promising dynamic actuations of tubular devices.