Abstract
Tunable and responsive surfaces offer routes to multiple functionalities ranging from superhydrophobic surfaces to controlled adhesion. Inspired by cilia structure in the respiratory pathway, magnetically responsive periodic arrays of flexible and magnetic thiol-ene micropillars are fabricated. Omnidirectional collective bending of the pillar array in magnetic field is shown. Local non-contact actuation of a single pillar is achieved using an electromagnetic needle to probe the responsiveness and the elastic properties of the pillars by comparing the effect of thiol-ene crosslinking density to pillar bending. The suitable thiol-ene components for flexible and stiff magnetic micropillars and the workable range of thiol-to-allyl ratio are identified. The wettability of the magnetic pillars can be tailored by chemical and topography modification of the pillar surface. Low-surface-energy self-assembled monolayers are grafted by UV-assisted surface activation, which is also used for surface topography modification by covalent bonding of micro- and nanoparticles to the pillar surface. The modified thiol-ene micopillars are resistant to capillarity-driven collapse and they exhibit low contact angle hysteresis, allowing water droplet motion driven by repeated bending and recovery of the magnetic pillars in an external magnetic field. Transport of polyethylene microspheres is also demonstrated.
Highlights
This material is protected by copyright and other intellectual property rights, and duplication or sale of all or part of any of the repository collections is not permitted, except that material may be duplicated by you for your research use or educational purposes in electronic or print form
UV-assisted surface activation, which is used for surface topography mod- between thiol and allyl groups in a mixture ification by covalent bonding of micro- and nanoparticles to the pillar surface
The modified thiol–ene micopillars are resistant to capillarity-driven collapse and they exhibit low contact angle hysteresis, allowing water droplet motion driven by repeated bending and recovery of the magnetic pillars in an external containing two chemical components in its simplest form, one with thiol groups and the other with allyl groups mixed together in liquid form at stoichiometric or off-stoichiometric ratio
Summary
This material is protected by copyright and other intellectual property rights, and duplication or sale of all or part of any of the repository collections is not permitted, except that material may be duplicated by you for your research use or educational purposes in electronic or print form. Composition of above 80% thiol excess did not fully cure (Figure S3, Supporting Information) and the adhesion between thiol–ene layer and the PDMS mold became high with 50–80% thiol excess causing the pillars to tear up during separation.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
