Focal position control of ultrasonic transducer made of plano-concave form piezoelectric vibrator

A wireless ultrasound energy harvester based on flexible relaxor ferroelectric crystal composite arrays for implanted bio-electronics

“…3(d), the acoustic pressure at the focal point is much higher than that at other positions, thus the Nd-PUEH should be placed near the focal point to improve the ultrasonic energy harvesting efficiency. 43,44 As simulated in Fig. S7 and Supplementary Video S1 (ESI†), the piezo-elements of helix-structure located on or near the focus point show higher strain than others.…”

Design and micromanufacturing technologies of focused piezoelectric ultrasound transducers for biomedical applications

“…To address limitations of the ball pressing method, the mechanical grinding technique was developed, utilizing a high-strength object to gradually wearing down the piezoelectric material until the desired curved shape is achieved. That is, a highstrength object is used to grind the surface of the piezoelectric material until a curved shape is formed [86,87]. For piezoelectric ceramics and piezoelectric single crystals of tens of micrometers, this method has absolute advantages, but for ultra-thin piezoelectric ceramics with thickness less than 10 micrometers, this method will not be applicable.…”

Acoustic Field Visualisation Using Local Absorption of Ultrasound and Thermochromic Liquid Crystals

“…In the late 1970s research on using LCs to map ultrasound shifted towards using nematic LCs [21], because nematic LCs, being directly sensitive to pressure, were more sensitive in the water bath arrangements used at the time, leading to the development of acoustography [22]. TLCs have been revisited more recently for beam profile mapping, again in water baths [23,24,25], with similar measurements performed using plates with thermochromic dye (not TLC) [26,27]. The mechanism behind the ultrasound visualisation in TLC is thermal.…”