Cryo-attachment for Scanning Electron Microscope
Electron microscopes are used by researchers all around the country and have been a major factor in the Institute’s success so far. The cryo-attachment is one of two new features of the electron microscope facility at Victoria University. It allows researchers to take images of soft materials and fluids.
About the Instrument:
Without a cryo-attachment it is impossible to take electron microscope images of liquids, soft materials or biological tissue. Because of the extremely high vacuum in the microscope the sample would blow up like a small bomb. This cryo-attachment freezes samples of liquid or soft material so quickly that its internal structure gets locked into solid form. Once frozen, the sample is fractured to reveal its internal structure and coated with a very thin layer of conductive platinum ready for scanning. The SEM has resolution of the order of 1 nanometre to 10 microns. It is a very expensive preparation stage but it opens up a world of possibilities.
The world is full of complex liquids and soft materials from biological tissue to mayonnaise. The key to understanding why these materials feel and behave the way they do often lies in their microscopic structure – the shape, size and packing of the molecules that make them up. The cryo-attachment finally allows scientists to see this structure with their own eyes. Victoria University chemist Kate McGrath and her group are using the facility to image liquid-based self-assembling systems such as emulsions and liquid crystals. The results of many of the other analytical techniques that Kate uses on these materials can be complicated and ambiguous. Having a visual picture of the system is a huge help. It’s a perfect complement to the other techniques available at Victoria University such as Nuclear Magnetic Resonance (NMR), particle size analysis and X-ray spectroscopy. They now have a unique and world class suite of equipment for soft materials research.
The cryo-attachment should be a great advantage for the MacDiarmid Institute’s BioNanoNetwork. It gives physical scientists, who are familiar with electron microscopy and nanoscience, an excuse to collaborate with biological scientists to shed new light on biological problems. Kate herself is a member of the Riddet Institute, the Centre of Research Excellence for food, nutrition and health research. Much of her work on soft materials has great relevance to the food industry
When someone says they are studying soft materials, you may think of cuddly toys or velvet cushions, but to MacDiarmid researchers it means the long chains of molecules that make up cellulose fibres, dairy-based casein micelles and protein filaments in hair or food. These biomaterials form an intermediary hierarchy between the atomic and single molecule […]