Piezoelectric devices are use in a wide range of medical application. Nowadays, most of the medical ultrasound transducers have the dual capacity to generate and receive an electric charge. However, other areas as surgical devices, dermatology and cosmetology, drug delivery, and laser ophthalmology; also incorporate piezoelectric devices in their treatment, prevention, or diagnostic of patients.
In 1880, Jacques and Pierre Curie published their experiments related to piezoelectricity; but the first practical application was in World War I. The technology was used to create an ultrasonic submarine detector. Since then piezoelectric devices have been use in a large range of applications.
The piezoelectric devices are those that use the piezoelectric effect to generate an electric charge under a mechanic stress, or vice versa. There are natural and man made materials that exhibit directly this effect, the most notably are crystal and certain ceramic, bone included. The especial characteristic of not been influenced neither create electromagnetic interference make piezodevices ideal for medical and biotechnology applications, as mention in Piezo motors & actuators.
Silently, the piezoelectric devices have been putting in our lives. Its progressive improvement has become a worldwide engine for innovation, enabling the development of new elements for the increasingly sophisticated applications. The realization in 1946 of the characteristics that the mixed ferroelectric barium titanate compound oxide (BaTiO3) could be converted to an electrical piezoelectric by poling process allowed the surprising admission of the piezo technology to the market, as presented in Chapter 1 of Piezoelectricity.
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As mention before piezodevices have advantages when use in medical equipment. However, among of them some have more attributes than others do, that are the case of ultrasonic linear piezomotors (also called resonant motors) and piezo stepper motors. Both are different in design, specifications, and performance according to Jim McMahon.
Ultrasonic piezomotors use a piezoelectric ceramic material to produce high-frequency acoustic vibrations and these create linear or rotary motion. They are use for large travel ranges, particularly when high speed is a requirement. Ultrasonic drives are considerably smaller than conventional electromagnetic motors. For detailed description of its operation click here
On the other hand, piezo stepper motors are form by numerous individual piezoactuators and generate motion through a succession of coordinated clamp/unclamp and expand/contract cycles. The motor could reach continuous motion when the actuators run at a high frequency. Physik Instrumente had developed the PiezoWalk, a piezo stepper motor, that can achieve much higher forces of up to 700 N compared with ultrasonic piezomotors.
On the other hand, piezo stepper motors are form by numerous individual piezoactuators and generate motion through a succession of coordinated clamp/unclamp and expand/contract cycles. The motor could reach continuous motion when the actuators run at a high frequency. Physik Instrumente had developed the PiezoWalk, a piezo stepper motor, that can achieve much higher forces of up to 700 N compared with ultrasonic piezomotors.
After a general view of piezo devices, we are ready to know how this technology change and improve the medical treatments and diagnostics.
