Anqi studied materials science and engineering in Beijing University of Aeronautics and Astronautics, China, and obtained her BSc in 2007. In the same year, she went to the School of Metallurgy and Materials, University of Birmingham, UK, for a PhD, where now she is a final year student.

Bacterial Biomineralisation of Hydroxyapatite on Titanium

Biomineralisation by Serratia bacteria sp. NCIMB 40259 is applied to coat titanium with hydroxyapatite (HA). A biofilm was pre-grown on Al2O3 grit blasted pure titanium discs in an airlift fermenter for five days. The samples were then transferred into a bioreactor to allow the synthesis of HA in a mineralisation solution. The crystal coated titanium discs were heat treated to burn off the biomass, as well as to sinter the coating crystals.

The as-synthesised crystals on the titanium surface were observed to be nanoneedle shaped calcium deficient hydroxyapatite. The crystal coating maintained itself well after the heat treatment, although the morphology changed from nanoneedles to nanoparticles. A transition layer around 2µm thick was found at the interface between the calcium phosphate coating and the titanium substrate, composed mainly of titanium and phosphorus.

Back to 2010 finalists