Ionic Polymer Microactuator Activated by Photoresponsive Organic Proton Pumps

Actuators

Khaled M. Al-Aribe²  George K. Knopf³  Amarjeet S. Bassi¹ 

[1] Department of Chemical and Biochemical Engineering, the University of Western Ontario, London, Ontario N6A 5B9, Canada; E-Mail:;Department of Mechanical Engineering, Abu Dhabi University, Abu Dhabi, United Arab Emirates; E-Mail:;Department of Mechanical and Materials Engineering, the University of Western Ontario, London, Ontario N6A 5B9, Canada

关键词: microfluidics;    lab-on-chip;    bacteriorhodopsin;    proton pumps;    molecular self-assembly;    micro-actuation;    pH-sensitive hydrogels;   

DOI  :  10.3390/act4040237

来源: mdpi

【 摘 要 】

An ionic polymer microactuator driven by an organic photoelectric proton pump transducer is described in this paper. The light responsive transducer is fabricated by using molecular self-assembly to immobilize oriented bacteriorhodopsin purple membrane (PM) patches on a bio-functionalized porous anodic alumina (PAA) substrate. When exposed to visible light, the PM proton pumps produce a unidirectional flow of ions through the structure’s nano-pores and alter the pH of the working solution in a microfluidic device. The change in pH is sufficient to generate an osmotic pressure difference across a hydroxyethyl methacrylate-acrylic acid (HEMA-AA) actuator shell and induce volume expansion or contraction. Experiments show that the transducer can generate an ionic gradient of 2.5 μM and ionic potential of 25 mV, producing a pH increase of 0.42 in the working solution. The ΔpH is sufficient to increase the volume of the HEMA-AA microactuator by 80%. The volumetric transformation of the hydrogel can be used as a valve to close a fluid transport micro-channel or apply minute force to a mechanically flexible microcantilever beam.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.