Magnetically actuated surface microstructures for efficient transport and tunable separation of droplets and solids

Kravanja, Gaia (author), Kriegl, Raphael (author), Hribar, Luka (author), Glavan, Gašper (author), Drevenšek Olenik, Irena (author), Shamonin, Mikhail (author), Jezeršek, Matija (author)

Efficient transportation of droplets (≈10$^1$–10$^2$ μL) and small solid objects (≈10$^1$–10$^2$ mm$^3$) have important applications in many fields, such as microfluidics, lab-on-a-chip devices, drug delivery, etc. A novel multifunctional surface consisting of a periodic array of micro-lamellae from a soft magnetoactive elastomer on a plastic substrate is reported for these purposes. The physical origin of the propulsion is the bending of soft magnetic lamellae in nonuniform magnetic fields, which is also observed in uniform magnetic fields. The magnetoactive surface is fabricated using a facile and rapid method of laser ablation. The propulsion of items is realized using a four-pole rotating magnet. This results in a cyclic lamellar fringe motion over the microstructured surface and brings an advantage of easy reciprocation of transport by rotation reversal. Two modes of object transportation are identified: “pushing” mode for precise control of droplet and solid positioning and “bouncing” mode for heavier solid objects transportation. A water droplet of 5 μL or a glass sphere with a 2.1 mm diameter can be moved at a maximum speed of 60 mm s$^{–1}$. The multifunctionality of the proposed mechatronic platform is demonstrated on the examples of selective solid–liquid separation and droplet merging.

• Language: English
• Keywords: magnetoresponsive surfaces, laser micromachinings, object transportations, object separations, magnetoactive elastomers
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering; FMF - Faculty of Mathematics and Physics
• Publication status: Published
• Publication version: Version of Record
• Year: 2023
• Number of pages: 11 str.
• Numbering: Vol. 25, iss. 22, art. 2301000
• PID: 20.500.12556/RUL-152633
• UDC: 620.3
• ISSN on article: 1438-1656
• DOI: 10.1002/adem.202301000
• COBISS.SI-ID: 167150595
• Publication date in RUL: 01.12.2023

Record is a part of a journal

• Title: Advanced engineering materials
• Shortened title: Adv. eng. mater.
• Publisher: Wiley
• ISSN: 1438-1656
• COBISS.SI-ID: 21394693

Licences

• License: CC BY-NC 4.0, Creative Commons Attribution-NonCommercial 4.0 International
• Link: http://creativecommons.org/licenses/by-nc/4.0/
• Description: A creative commons license that bans commercial use, but the users don’t have to license their derivative works on the same terms.

Secondary language

• Language: Slovenian
• Keywords: magnetoaktivni elastomeri, magnetno odzivne površine, lasersko mikrostrukturiranje, transport, separacija