Good impression

Miniaturisation is a continuing trend in many areas of technology, but researchers at the

have found that making things smaller can also make them faster. Testing the mechanical properties of materials is a time-consuming task, but according to the MIT team, reducing the size of the samples cuts the time needed to screen a large number of materials from weeks to days.

The technique grew out of biotechnology research. Looking for a material to support the growth of human stem cells, chemical engineers Daniel Anderson and Robert Langer made what’s known as a combinatorial array of compounds —very small quantities of related materials, deposited using automated equipment on to a glass slide.

Their research caught the eye of materials scientist Krystyn Van Vliet, whose laboratory specialises in how the surface features of a material affect the way it supports cell growth.

One of the most important parameters for this is the surface hardness, which Van Vliet tests using a nanoindenter. Analoguous to the standard indentation test for materials, nanoindentation provides the same information about properties such as elasticity and hardness, but requires much smaller amounts of material.