We investigate the harvesting of sound waves by exploiting a 3D-printed gradient-index phononic crystal lens. The concept is demonstrated numerically and experimentally for focusing audio frequency range acoustic in air to enhance energy harvesting. A finite-element model developed design unit cell dispersion properties construct 3D lens wave field simulations. Numerical simulations are present...

Abstract The steady-state vibration amplitude is an important performance indicator of high-frequency ultrasonic transducers for ultrasonically assisted manipulating, machining, and manufacturing. This work aimed to develop a calculation model the new type dual-branch cascaded composite structure-based transducer that can be used in packaging microelectronic chips. First, piezoelectric vibrator...

Our sweep design methodology centers on creating a frequency dependent force-amplitude (drive) function such that the drive-level at each frequency is maximised but does not exceed the mechanical limitations of the vibrator. Bagaini (2008) showed how we can overcome the reduction in energy from reducing the drive-level by increasing the instantaneous sweep rate. This methodology has commonly be...

The present work experimentally investigates the thermal effects of a synthetic jet actuator on the heat transfer performance of single-phase flow confined in a microchannel heat sink. The heat sink consisted of a single rectangular microchannel 500 μm wide, 300 μm deep and 26 mm long. Deionized water was employed as the cooling fluid. A synthetic jet actuator with a 100 μm diameter orifice was...

This paper describes a minimalist mobile robot design approach that offers a high locomotive efficiency, and is therefore well suited to mesoscale robot design. The authors have incorporated this approach into the development of a dynamically controlled piezoelectrically actuated mesoscale robot quadruped. The design described utilizes a lightly damped skeletal structure that generates locomoti...

This paper presents the design, simulation and characterization of a new type of in-plane thermal unimorph, which utilizes composite SU-8/silicon microstructures. The unimorph consists of a silicon skeleton and SU-8 photoresist, which encapsulates the silicon skeleton. The silicon skeleton is asymmetric in shape, consisting of a straight segment and a meandering segment. Gaps and surrounds of t...

This paper presents novel micromachined two-dimensional array piezoelectrically actuated flextensional transducers that can be used to generate sound in air or water. Micromachining techniques to fabricate these devices are also presented. Individual unimorph array elements consist of a thin piezoelectric annular disk and a thin, fully clamped, circular plate. We manufacture the transducer in t...

The emergence and evolution of energy micro-generators during the last 2 decades has delivered a wealth harvesting powering solutions, with capability exploiting wide range motion types, from impulse low frequency irregular human motion, to broadband vibrations ultrasonic waves. It also created background engineering microsytems, including fabrication methods, system concepts optimal functional...