Wireless power technology offers the promise of cutting the last cord, allowing users to seamlessly recharge mobile devices as easily as data are transmitted through the air. Initial work on the use of magnetically coupled resonators for this purpose has shown promising results. We present new analysis that yields critical insight into the design of practical systems, including the introduction of key figures of merit that can be used to compare systems with vastly different geometries and operating conditions. A circuit model is presented along with a derivation of key system concepts, such as frequency splitting, the maximum operating distance (critical coupling), and the behavior of the system as it becomes undercoupled. This theoretical model is validated against measured data and shows an excellent average coefficient of determination of 0.9875. An adaptive frequency tuning technique is demonstrated, which compensates for efficiency variations encountered when the transmitter-to-receiver distance and/or orientation are varied. The method demonstrated in this paper allows a fixed-load receiver to be moved to nearly any position and/or orientation within the range of the transmitter and still achieve a near-constant efficiency of over 70% for a range of 0-70 cm.

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Analysis, Experimental Results, and Range Adaptation of Magnetically Coupled Resonators for Wireless Power Transfer

This article reviews acoustic microfiuidics: the use of acoustic fields, principally ultrasonics, for application in microfiuidics. Although acoustics is a classical field, its promising, and indeed perplexing, capabilities in powerfully manipulating both fluids and particles within those fluids on the microscale to nanoscale has revived interest in it. The bewildering state of the literature and ample jargon from decades of research is reorganized and presented in the context of models derived from first principles. This hopefully will make the area accessible for researchers with experience in materials science, fluid mechanics, or dynamics. The abundance of interesting phenomena arising from nonlinear interactions in ultrasound that easily appear at these small scales is considered, especially in surface acoustic wave devices that are simple to fabricate with planar lithography techniques common in microfluidics, along with the many applications in microfluidics and nanofluidics that appear through the literature.

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Microscale acoustofluidics: Microfluidics driven via acoustics and ultrasonics

The effects of music training in relation to brain plasticity have caused excitement, evident from the popularity of books on this topic among scientists and the general public. Neuroscience research has shown that music training leads to changes throughout the auditory system that prime musicians for listening challenges beyond music processing. This effect of music training suggests that, akin to physical exercise and its impact on body fitness, music is a resource that tones the brain for auditory fitness. Therefore, the role of music in shaping individual development deserves consideration.

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Music training for the development of auditory skills

The Evolution of Language

Polymer based MEMS and microfluidic devices have the advantages of mechanical flexibility, lower fabrication cost and faster processing over silicon based ones. Also, many polymer materials are considered biocompatible and can be used in biological applications. A valuable class of polymers for microfabricated devices is piezoelectric functional polymers. In addition to the normal advantages of polymers, piezoelectric polymers can be directly used as an active material in different transduction applications. This paper gives an overview of piezoelectric polymers based on their operating principle. This includes three main categories: bulk piezoelectric polymers, piezocomposites and voided charged polymers. State-of-the-art piezopolymers of each category are presented with a focus on fabrication techniques and material properties. A comparison between the different piezoelectric polymers and common inorganic piezoelectric materials (PZT, ZnO, AlN and PMN?PT) is also provided in terms of piezoelectric properties. The use of piezopolymers in different electromechanical devices is also presented. This includes tactile sensors, energy harvesters, acoustic transducers and inertial sensors.

https://iopscience.iop.org/article/10.1088/0964-1726/23/3/033001/pdf

A review of piezoelectric polymers as functional materials for electromechanical transducers

Part I: Vibrating Systems. Free and Forced Vibrations of Simple Systems. Continuous Systems in One Dimension: Strings and Bars. Two-Dimensional Systems: Membranes, Plates, and Shells. Coupled Vibrating Systems. Nonlinear Systems.- Part II: Sound Waves. Sound Waves in Air. Sound Radiation. Pipes, Horns, and Cavities.- Part III: String Instruments. Guitars and Lutes. Bowed String Instruments. Harps, Harpsicords, Clavicords, and Dulcimers. The Piano.- Part IV: Wind Instruments. Sound generation by Reed and Lip Vibrations. Lip-driven Brass Instruments. Woodwind Reed Instruments. Flutes and Flue Organ Pipes. Pipe Organs.- Part V: Percussion Instruments. Drums. Mallet Percussion Instruments. Cymbals, Gongs, Plates, and Steel Drums. Bells.- Part VI: Materials. Materials for Musical Instruments.- Name Index.- Subject Index.

The Physics of Musical Instruments

Acoustics, the science of sound, has developed into a broad interdisciplinary field encompassing the academic disciplines of physics, engineering, psychology, speech, audiology, music, architecture, physiology, neuroscience, and others. The Springer Handbook of Acoustics is an unparalleled modern handbook reflecting this richly interdisciplinary nature edited by one of the acknowledged masters in the field, Thomas Rossing. Researchers and students benefit from the comprehensive contents spanning: animal acoustics including infrasound and ultrasound, environmental noise control, music and human speech and singing, physiological and psychological acoustics, architectural acoustics, physical and engineering acoustics, signal processing, medical acoustics, and ocean acoustics. This handbook reviews the most important areas of acoustics, with emphasis on current research. The authors of the various chapters are all experts in their fields. Each chapter is richly illustrated with figures and tables. The latest research and applications are incorporated throughout, e.g. computer recognition and synthesis of speech, physiological acoustics, psychological acoustics, thermoacoustics, diagnostic imaging and therapeutic applications and acoustical oceanography. With a Foreword by Manfred R. Schroeder

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Springer Handbook of Acoustics

Music Producers.(Book Reviews: The Physics of Musical Instruments.)

1 Free and Forced Vibrations of Simple Systems.- 2 Continuous Systems in One Dimension: Strings and Bars.- 3 Two-Dimensional Systems: Membranes and Plates.- 4 Coupled Vibrating Systems.- 5 Nonlinear Systems.- 6 Sound Waves in Air.- 7 Sound Radiation.- 8 Pipes and Horns.- 9 Acoustic Systems.- 10 Microphones and Other Transducers.- 11 Sound in Concert Halls and Studios.- 12 Sound and Noise Outdoors.- 13 Underwater Sound.- Selected Bibliography.- Problems.- Answers to Selected Problems.- Name Index.

Thomas D. Rossing

Papers

The Physics of Musical Instruments

Springer Handbook of Acoustics

The Physics of Musical Instruments

Music Producers.(Book Reviews: The Physics of Musical Instruments.)

Principles of Vibration and Sound