Vibration sensing paint: how does it work

A.� A new paint has been developed that’s designed to sense vibrations. The paint contains a fine powder of piezoelectric material called lead zirconate titanate (PZT).

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When PZT crystals come under pressure that stretches or squeezes them, they produce an electrical signal, which is representative of the amount of force being applied. The paint is charged so that the crystals align themselves at right angles to the surface, ensuring that, regardless of the direction of stress, the PZT crystals produce a signal.

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Q.� What is a piezoelectric material

A.� One that creates an electric voltage when hit or vibrated.

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Q.� What uses does the paint have

A.� It's hoped that the paint will help engineers build lighter, cheaper and more aesthetic bridges and oilrigs. At the moment these structures are prone to cracks caused by vibrations, any weakness could have a devastating affect.

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As a result engineers tend to make oilrigs and bridges stronger than they need to be to make them extra safe.

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Q.� How long does the paint work for

A.� Indefinitely, which means that engineers will be able to a monitor the stress a structure is under and more accurately estimate when it is likely to be unusable.

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Q.� Is vibration stress currently measured

A.� Yes, using strain gauges. The problem is that if they're incorrectly fitted they give false readings.

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Q.� Will the paint solve the problem

A.� Because the paint measures strain from all directions simultaneously it won't be possible to determine which direction the strongest vibrations comes from, which could be confusing. However this shouldnt present too much of a problem because many strain patterns are unidirectional.

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Have you heard about a new scientific product and want to know how it works Just click here to ask.

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by Lisa Cardy