Andrew Feeney, PhD, earned a master’s in mechanical engineering with honours of the first class at the University of Glasgow in the United Kingdom in 2010 and a PhD in mechanical engineering in 2014 at the same institution, investigating the incorporation of the shape memory alloy Nitinol in flextensional cymbal transducers for the eventual development of tuneable ultrasonic devices. This research laid the groundwork for this book. Since then, Dr Feeney has undertaken several cross-disciplinary postdoctoral research projects in a range of application areas including ultrasonic surgery and subsea exploration. In 2016, he joined the Centre for Industrial Ultrasonics as Research Fellow in the Department of Physics at the University of Warwick, leading a new area of research activity in high-frequency flexural ultrasonic transducers. During this time, he collaborated with several industry partners to engineer novel configurations of the flexural ultrasonic transducer for hostile environments, including those of elevated pressure and temperature. This research significantly expanded the practical application of the flexural ultrasonic transducer beyond their traditional uses in automotive systems. In 2020, Dr Feeney joined the Centre for Medical and Industrial Ultrasonics as Lecturer/Assistant Professor in the James Watt School of Engineering at the University of Glasgow before being promoted to Senior Lecturer/Associate Professor in 2023. Dr Feeney leads the Adaptive Ultrasonics (Adaptus) Research Group, which tackles key challenges in engineering adaptive ultrasonic devices and systems for a new generation of intelligent, multifunctional, and tuneable medical and industrial technologies. The Adaptus Research Group undertakes fundamental research on advanced materials, principally those which exhibit shape memory behaviour, and metamaterials. Dr Feeney’s research group focuses on the integration of these materials with a broad range of acoustic and ultrasonic devices and electromechanical systems in order to tailor and optimise dynamic performance. The Adaptus Research Group is centred around four principal themes: shape memory alloys and metamaterials, medical devices, industrial sensors and actuators, and sustainable manufacturing. Dr Feeney’s research group includes several postdoctoral researchers and doctoral students, and his research is funded by grants from a combination of UK Research and Innovation, European Research Council, and industry in the order of millions GBP. At the time of publication, Dr Feeney is a Chartered Engineer and Member of the Institution of Mechanical Engineers (IMechE) and a Member of the Institution of Electrical and Electronics Engineers (IEEE). He has published over 50 peer-reviewed journal and conference articles, is a regular peer reviewer of the major journals in the fields of ultrasonics, ferroelectrics, mechatronics and interdisciplinary science, and is a reviewer of grant proposals for UK Research and Innovation, principally the Engineering and Physical Sciences Research Council.