Waves in complex materials can often behave in strange ways, which continue to fascinate us and enrich our basic understanding of wave physics. Examples range from strikingly large variations in wave speeds to the remarkable trapping of waves by disorder. Other extraordinary effects include negative refraction, in which waves bend the opposite way to normal, and superabsorption, enabling partial cloaking of objects.

Ultrasonic techniques are well suited for investigating such phenomena since complete information on how waves travel, or not, can be measured directly in samples with well controlled structures. 

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In this talk, Dr. Page will summarize recent progress in understanding ultrasonic wave transport in both ordered and disordered synthetic materials, such as phononic crystals, metamaterials and “mesoglasses”, where experiments on carefully designed and fabricated model systems are yielding new insights into how materials can influence and control the fundamental properties of waves. The results of these fundamental studies on wave behaviour in complex media is aiding the development of new ultrasonic spectroscopic techniques for probing the structure and dynamics of heterogeneous materials, including soft food biomaterials.