Thermoacoustic Effects and Applications in Medicine, Security and Communication

Thermoacoutsic effect describes the generation of acoustic waves from incident electromagnetic energy due to differential heat generation and absorption in an object. Thermoacoustic imaging (TAI) is a promising candidate for many biomedical applications including breast cancer detection. TAI creates an image of the internal morphological features of a dielectrically lossy sample by employing generated acoustic waves from absorbed microwave energy in the sample owing to the thermoacoustic effect based on thermoelastic expansion. Malignant tissues, usually embracing higher dielectric loss, absorbing more energy and emanating stronger acoustic waves than the surrounding healthy tissues, may be distinguished in the image. The elegant marriage between microwave and ultrasound, whose advantages and drawbacks in biomedical imaging are in many ways complementary, endows TAI with the unique merit of high contrast inherited from microwave and excellent spatial resolution inherited from ultrasound. TAI is also non-ionizing and noninvasive compared with other existing breast cancer imaging modalities. A potential clinical feasible TAI system is more cost-efficient and compact than mammography and MRI.

In addition, we explore another novel potential application based on thermoacoustic effect for wireless communications, which is referred to as thermoacoustic communications (TAC). It is proposed as a potential complementary method to mitigate the challenge in conventional wireless communication from air to water, in which the electromagnetic wave cannot penetrate deep in water. TAC employs a microwave antenna in air to irradiate the water surface with a microwave signal encoded with information to be communicated. Some microwave energy is absorbed by the water and concomitant temperature increase and thermal expansion take place in the water. Acoustic waves are subsequently emanated from the water and propagate in the water with much less attenuation than electromagnetic waves and thus can propagate a long distance in the water.

Finally, an underwater device with an acoustic transducer can detect the generated acoustic signals and the information is acquired by decoding the signals. In this talk, I will present our theoretical and experimental studies on thermoacoustic effect and its applications

Speaker(s): Prof Hao Xin,

Room: 401, Bldg: ITE, UConn, Storrs, Connecticut, United States