Thermoacoustic System

A thermoacoustic system for probing an electrically conductive sample, the system comprising:

• a first electrical conductor formed of a dissimilar material to that of the sample;
• and
• an electronic signal generator;
• wherein:
• the first electrical conductor is movable to a contact position at which it contacts the sample to form an electrical junction at an interface therebetween;
• and
• the electronic signal generator is configured to generate a driving signal across the electrical junction, to generate an acoustic wave that enters the sample from the interface.

A thermoacoustic system comprising:

• a pair of electrical conductors comprising a first electrical conductor and a second electrical conductor formed of dissimilar materials, wherein the first and second electrical conductors connect at an interface to form an electrical junction;
• an electronic signal generator for generating a driving signal across the electrical junction;
• and
• a detector configured to detect a thermoelectric voltage or current that is induced across the electrical junction in response to an acoustic wave impinging the system at the interface.