Biomimetics – Understanding the nano-porous structures
of diatom species for filtration
Hemant Bhatta, Gary Rosengarten, University of New South Wales
This project uses microfluidic flow visualisation methods coupled with numerical models to
help understand the role of pore architecture in the filtration mechanism of diatoms (select
species). The prime aim is to determine if can we be guided to an optimum membrane
structure for a given separation process, by studying and understanding some of nature’s
• A fundamental membrane flow visualisation technique to help characterise and
understand the fundamental properties and performance membranes.
• The use of nature to gain an understanding of the properties that will allow for the
most efficient separation and filtration method
Progress to date.
• Fluorescence microscopy and fluorescence correlation spectroscopy (FCS) results
showing the diffusion of dye molecules through the nano-pores of the diatoms.
• The boundary conditions of the pore architecture seem to change the effective
• Microfluidics setup with capillary fibre to study the diffusion through diatoms or any
0 200 400 600 800 1000 1200
Diatom Stuck Capillary (2 layers), D=3.1x10
Diatom Stuck Capillary (1 layer)
Open End Capillary, D=4.14x10
Fluorescence Intensity (a.u.)
Left: Plot of fluorescence intensity vs time for open-end capillary (top curves), single layer diatom
stuck capillary (middle curves) and double layer diatom stuck capillary (bottom curves). The
continuous lines represent the theoretical curves and the symbols represent the experimental data.
Right: Diatom frustule showing nanopores on the inside and outside.
Cooperation is sought to
• Microfabricate a generic device that could be used for diffusion studies or particle flow
visualization through diatom and/or other biological/non-biological membranes.
Contact: Dr. Gary Rosengarten