Artificial Organic Skin Wets Its Surface by Field-Induced Liquid Secretion

Yuanyuan Zhan; Guofu Zhou; Brigitte A G Lamers; Fabian L L Visschers; Marco M R M Hendrix; Dirk J Broer; Danqing Liu

doi:10.1016/j.matt.2020.05.015

Artificial Organic Skin Wets Its Surface by Field-Induced Liquid Secretion

Matter. 2020 Sep 2;3(3):782-793. doi: 10.1016/j.matt.2020.05.015.

Authors

Yuanyuan Zhan^{1

2}, Guofu Zhou^{1

2}, Brigitte A G Lamers^{3

4}, Fabian L L Visschers^{2

3}, Marco M R M Hendrix⁵, Dirk J Broer^{1

2

3}, Danqing Liu^{1

2

3}

Affiliations

¹ SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, PR China.
² Laboratory of Stimuli-Responsive Functional Materials and Devices (SFD), Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Groene Loper 3, 5612 AE Eindhoven, the Netherlands.
³ Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Groene Loper 3, 5612 AE Eindhoven, the Netherlands.
⁴ Laboratory of Macromolecular and Organic Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Groene Loper 3, 5612 AE Eindhoven, the Netherlands.
⁵ Laboratory of Physical Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Groene Loper 3, 5612 AE Eindhoven, the Netherlands.

Abstract

Living organisms enhance their survival rate by excreting fluids at their surface, but man-made materials can also benefit from liquid secretion from a solid surface. Known approaches to secrete a liquid from solids are limited to passive release driven by diffusion, surface tension, or pressure. Remotely triggered release would give active control over surface properties but is still exceptional. Here, we report on an artificial skin that secretes functional fluids by means of radiofrequency electrical signals driven by dielectric liquid transport in a (sub-)microporous smectic liquid crystal network. The smectic order of the polymer network and its director determine the flow direction and enhance fluid transport toward the surface at pre-set positions. The released fluid can be reabsorbed by the skin using capillary filling. The fluid-active skins open avenues for robotic handling of chemicals and medicines, controlling tribology and fluid-supported surface cleaning.

Keywords: artificial polymer skin; chemical release; liquid crystal network; liquid secretion; radio frequency electric field.