Quartz purity test makes microtechnique news

Much microtechnique news focuses on imaging objects - but a team at the National Institute of Standards and Technology (NIST) has been working recently on a method of establishing the purity of very small quantities of material.

The technique is a variation on thermogravimetric analysis, in which the changes in a sample as it is heated are used to calculate its oxidation, dehydration or decomposition energy.

In the latest microtechnique news to come from the project, the NIST scientists say they can alter the ultrasonic pitch of quartz by placing a sample on its surface and then heating it.

What they have created, in effect, is a set of weighing scales similar to those in kitchens worldwide, but capable of measuring masses to within a small number of micrograms.

NIST has played a significant role in the development of imaging technologies in the past, including scanning tunnelling microscopy and X-ray mammography.