The use of the expansion of lithium-ion cells for mechanical actuation has been recently reported by Chin et. al. (1). Under a stress of 10 MPa, actuating strains of up to 1.5% were achieved. Taking into account the cells approximate elastic modulus, this strain corresponds to a mechanical energy density ten times higher than that of current piezoelectric materials, although with slower actuati...

Metamaterials are artificially structured materials and exhibit properties that uncommon or non-existent in nature. Mechanical metamaterials show exotic mechanical properties, such as negative stiffness, vanishing shear modulus, Poisson’s ratio. These stem from the geometry arrangement of metamaterial unit elements and, therefore, cannot be altered after fabrication. Active aim to overcome this...

Mathematical models and circuitry necessary for optimal energy conversion have been developed for piezoelectric devices because of their ability to convert mechanical energy to electrical energy. The piezoelectric device that is the focus of this study is a curved, thin unimorph prestressed bender. This device consists of layers of piezoelectric material, polyimide, and metal bonded at high tem...

Design, fabrication and tests of a monolithic compliant-flexure-based microgripper were performed. The geometry design and the material tresses were considered through the finite element analysis. The simulation model was used to study in detail profiles of von Mises stresses nd deformation. The maximum stress in the microgripper is much smaller than the critical stress values for fatigue. The ...

A novel vertical translational microactuator based on thin-film piezoelectric actuation is presented, using a set of four compound bend-up/bend-down unimorphs to produce translational motion of a moving platform or stage. The actuation material is a chemical-solution deposited lead-zirconate-titanate (PZT) thin film. Prototype designs have shown as much as 120 μm of static displacement, with 80...

A piezoelectric dispenser has been fabricated based on the idea of a piezoelectric-metal-cavity (PMC) actuator. The PMC actuator consists of a metal ring sandwiched between two identical piezoelectric unimorphs. The radial contraction of the piezoelectric ceramic is converted into a flextensional motion of the unimorph, causing a large flexural displacement in the center part of the actuator. W...

Currently, most of the integrated sorting modules in the microfabricated DEP-based and fluorescent-activated cell sorters (μFACS) still suffer from low-throughput operation and require complex fabrication process (e.g. embedded electrodes) and high power consumption (e.g. electrokinetically-driven sorters). In this paper, we demonstrate an easy-to-fabricate, low-powered and high-speed sorting m...

This paper is concerned with the development of a piezoelectric d15 shear-induced torsion actuator made of a lead-free piezoceramic material exhibiting giant piezoelectric shear stress coefficient (e15) and piezoelectric transverse shear actuation force comparable to that of lead-based shear-mode piezoceramics. The Mn-modified 0.93(Na0.5Bi0.5TiO3)-0.07BaTiO3 (NBT-BT-Mn) composition exhibited ex...

Piezoelectric thin films offer a number of advantages in various applications, such as high energy density harvesters, a wide dynamic range, and high sensitivity sensors, as well as large displacement and low power consumption actuators. This review covers the available material forms and applications of piezoelectric thin films: lead zirconate titanate (PZT)-based thin films, lead-free piezoel...