RSC_Materials Horizons


RSC_Materials Horizons

01 September 2022, Issue 9,

Page 2245 to 2462

Tailoring matter orbitals mediated using a nanoscale topographic interface for versatile colloidal current devices

Conventional micro-particle manipulation technologies have been used for various biomedical applications using dynamics on a plane without vertical movement. In this case, irregular topographic structures on surfaces could be a factor that causes the failure of the intended control. Here, we demonstrated a novel colloidal particle manipulation mediated by the topographic effect generated by the “micro hill” and “surface gradient” around a micro-magnet. The magnetic landscape, matter orbital, created by periodically arranged circular micro-magnets, induces a symmetric orbit of magnetic particle flow under a rotating magnetic field. The topographic effect can break this symmetry of the energy distribution by controlling the distance between the source of the driving force and target particles by several nanometers on the surface morphology. The origin symmetric orbit of colloidal flow can be distorted by modifying the symmetry in the energy landscape at the switching point without changing the driving force. The enhancement of the magnetic effect of the micro-magnet array can lead to the recovery of the symmetry of the orbit. Also, this effect on the surfaces of on-chip-based devices configured by symmetry control was demonstrated for selective manipulation, trapping, recovery, and altering the direction using a time-dependent magnetic field. Hence, the developed technique could be used in various precise lab-on-a-chip applications, including where the topographic effect is required as an additional variable without affecting the existing control method.

  • Hyeonseol Kim
  • Yumin Kang
  • Byeonghwa Lim
  • Keonmok Kim
  • Jonghwan Yoon
  • Abbas Ali
  • Sri Ramulu Torati
  • CheolGi Kim

Materials Horizons  Home-Urgent short reports of exceptionally high quality &amp; innovative materials science.<br/><br/>Editorial Board Chair: Martina Stenzel<br/>Impact factor: 15.717<br/>Time to first decision (peer reviewed only): 36 days (

Image created by minjeong Kim / Nanosphere