Multilayer piezoelectric copolymer transducers

Monolithic fabrication of multilayer P(VDF-TrFE) cantilevers

“…(11) indicates that, for each flexural (mechanical) resonance there will be several peaks in a frequency plot due to the square wave signal. The frequency of the peaks will be…”

“…The cantilevers presented here are built with a batch fabrication technique [11] and have a larger size than the final legs of the locomotion module used for the I-SWARM robot. P(VDFTrFE) is chosen as it is compatible with several batch fabrication processes such as spin coating at room temperature and standard evaporating techniques for depositing electrode material.…”

Patterning microbeads inside poly(dimethylsiloxane) microfluidic channels and its application for immobilized microfluidic enzyme reactors

“…It involved a complicated fabrication procedure of microfluidic devices and those structures could often cause clogging. To exclude the use of mechanical barriers, some outside force fields such as ultrasonic [21], magnetic forces [22,23], and suction using a laser-drilled microcapillary [24] were introduced to microfluidic systems for trapping microbeads. In addition, some approaches for microbeads immobilization based on selfassembly [25,26] and hydrophobic adhesion in response to thermal stimulus [27] have also been reported.…”

Ultrasonic properties of all-printed piezoelectric polymer transducers

“…Ferroelectric polyvinylidenefluoride (PVDF) and its copolymer PVDF trifluoroethylene [P(VDF-TrFE)] are widely used for making ultrasonic sensors and transducers applied to nondestructive evaluation (NDE), underwater acoustic and medical imaging. [1][2][3][4][5][6][7][8][9] Although piezoelectric polymers have a considerable weaker piezoelectrical coupling than comparable ceramics, they have advantages in terms of being flexible, easy to process, and providing a relatively good acoustic match to water, human tissue, and many polymer materials. A large number of techniques have been explored for processing ferroelectric polymers into flexible film, such as spin coating, hot pressing, stamping, and spraying.…”

“…A large number of techniques have been explored for processing ferroelectric polymers into flexible film, such as spin coating, hot pressing, stamping, and spraying. [1][2][3][4][5][6][7] Electrodes can also be attached to the film surface by various methods, as, for example, sputter coating, vapor deposition, and printing. 4,6,[9][10][11][12][13][14] Some of the printing methods (e.g., screen-printing, ink-jet printing, and laser ablation) also facilitate electrode printing directly onto the backing substrate, with a potential reduction in processing steps and fabrication time.…”