Single cell creature is solar cell future

Ancient microscopic organisms are the tools of the future for the advancement of material science in areas such as solar cell technology.

And a 2008 honours student has published his proof of concept in the high-impact Journal of the American Chemical Society (JACS).

Jeremiah Toster, who was in the first cohort of bachelor of science students to study nanotechnology, has manipulated the silica shells of diatoms so that they can be used as platforms for developing useful materials in areas of health, energy and the environment.

He is embarking on his PhD in the Centre for Strategic Nano-fabrication (School of Biomedical, Biomolecular and Chemical Science) working on using diatom shells as a scaffold for solar cells.

His supervisors, Prof Colin Raston and Dr Iyer Swaminathan, were co-authors with Jeremiah of the article, which encapsulated his honours research.

Scientists around the world are exploring the use of materials reduced to the nanoscale, where they can show very different properties from those they exhibit at a normal scale.

But fabrication at the nanoscale (when a metre is equal to a billion nanometres) is difficult. The nanotechnology community is turning to the science of biomimicry, emulating nature to solve complex problems.

Diatoms, one such example, are single cell microscopic organisms found in both freshwater and saltwater ecosystems, and believed to be responsible for 25% of the total oxygen production on Earth.

They are the most abundant life form on the planet and their silica shells are readily available from geological deposits. They are perforated with pores measuring between 50 and 200 nm.

"These shells are in abundance, so why try to make them at nano-dimension, when nature has provided this perfect structure?" Pro Raston said.

"This material has been precisely engineered by nature but we need to be able to manipulate it," Jeremiah said.

So he developed a method for assembling gold nanoparticles around the pores of diatom shells. "We tried other metals but gold was the one that worked," he said.

Jeremiah found that he could effectively create three-dimensional arrays of gold nanoparticles using the diatom scaffold, which opens the door to developments in drug delivery and optical applicaitons as well as solar cell technology.

(Reprinted from UWA News of the University of Western Australia.)