A Passive Micromixer with Koch Snowflakes Fractal Obstacle in Microchannel

Document Type : Regular Article


1 Departement of Physics Education, Universitas Pendidikan Indonesia, Bandung, Jawa Barat, 40154, Indonesia

2 Departement of Electrical Engineering Education, Universitas Pendidikan Indonesia, Bandung, Jawa Barat, 40154, Indonesia

3 Engineering Physics, Institut Teknologi Bandung, Bandung, Jawa Barat, 40132, Indonesia

4 Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia (UKM), Bangi, Selangor, 43600, Malaysia



The passive micromixer is one of the essential devices that can be integrated into the Lab on Chip (LoC) system. Micromixer is needed to increase mixing efficiency. In this paper, two Koch fractal obstacle-based micromixer models of Secondary Snowflakes Fractal Micromixer (SSFM) and Tertiary Snowflakes Fractal Micromixer (TSFM) were designed. The effect of the Koch fractal resistance angles (15o, 30o, 45o, 315o, 330o, 345o) and the influence of the inlet (T and T-vortex) were studied in this paper using COMSOL Multiphysics numerical simulations. The results showed that the TSFM structure with a 30o angle on the T-vortex inlet is optimal. The deflection phenomena generated by the TSFM obstacle enhance the contact area between the two fluids and chaotic convection can be increased at Reynolds Number (Re) 0.05 and Re 100. This paper examines concentration curves along the channel ranging from 1 mol/L to 5 mol/L. This clearly shows that the fluid flow direction changes within the microchannel. This work provides a new design for the micromixer.


Volume 15, Issue 5
September and October 2022
Pages 1333-1344
  • Received: 08 December 2021
  • Revised: 06 May 2022
  • Accepted: 07 May 2022
  • First Publish Date: 26 June 2022