Active bacterial anti-adhesion strategy based on directional transportation of droplet self-actuated by Laplace pressure gradient on self-actuated and infrared sensing responsive platform

Abstract

The adhesion of adverse bacteria to material surfaces increases the risk of microbial corrosion and bacterial transmission. Superhydrophobic and superhydrophilic-type bacterial anti-adhesion approaches have been explored; however, these approaches are static and passive. This study proposes an active-bacterial anti-adhesion strategy based on the directional transportation of bacterial droplets on a star-shaped intelligent response platform (SIRP) for droplet self-actuation. Bacteria and other droplets can self-actuate on the SIRP, where droplets are in a superhydrophobic Cassie–Baxter wetting state, owing to the generated Laplace pressure gradient force on the wedge-shaped groove and extremely small adhesion resistance. The velocity and distance travelled of self-actuated droplets depend on various factors such as the opening angle, etching depth of the wedge-shaped groove, modified perfluorodecyltrimethoxysilane density, and droplet volume. Experimental and finite element simulation results confirm the continuous increase and sharp decrease in Laplace pressure difference in the self-actuated and non-self-actuated zones, respectively. The SIRP demonstrates superior bacterial anti-adhesion during bacterial droplet self-actuation and a very smart infrared-sensing sterilization or micro-reaction response to different types of droplets. The SIRP not only opens a new avenue for active bacterial anti-adhesion strategies but also offers a promising application for smart controllable micro-reactions.