Helical‐Like 3D Ultrathin Piezoelectric Element for Complicated Ultrasonic Field

Abstract

The developments of personalized medicine, ultrasound imaging, and contactless "microscopic handle" techniques are pushing ultrasonic transducers toward features of high frequency, device miniaturization, and even novel function. However, the conventional ultrasonic transducer has severely limited the development of novel ideas for applications due to its ordinary ultrasonic field. Although transducer arrays and monolithic acoustic holograms are capable of producing the complicated ultrasonic field, it is still difficult to achieve high frequency, device miniaturization, and novel function simultaneously. Here, a simple but effective approach is introduced that aims at reconstructing the complicated and high-frequency ultrasonic field via a compact single-element ultrasonic transducer. The 3D ultrathin piezoelectric element with a complex configuration is demonstrated theoretically and experimentally to produce the desired complicated ultrasonic field. With helical-like configuration, the single-element ultrasonic transducer offers efficient noncontact trapping and manipulation of suspended microparticles and biological cells. Moreover, its strong trapping capability leads to the 3D stacking of microparticles, which is a novel and interesting phenomenon achieved by a single-element ultrasonic transducer. This work brings the possibility of a complicated ultrasonic field for achieving novel high-frequency ultrasound applications through the design of smart structure ultrathin piezoelectric materials.

Dynamic Ultrasound Projector Controlled by Light

“…For example, an acoustic vortex beam is formed by a phase gradient and it is especially useful for particle manipulation [ 26 , 27 , 28 ] and underwater communication. [ 29 , 30 ] Conventional methods used to generate an acoustic vortex beam include static phase masks, [ 14 , 31 ] structured transducers, [ 28 , 32 ] and phased transducer arrays. [ 12 , 30 ] However, it remains challenging to realize dynamic and quickly reconfigurable vortex fields.…”

Potassium Sodium Niobate-Based Lead-Free High-Frequency Ultrasonic Transducers for Multifunctional Acoustic Tweezers

“…In personalized medicine, contact-free "microscopic handle" techniques require enhanced complex and precise operations with visualized edges, or small details of objects. 11 Because of their ability to conduct complex manipulations and precisely measure forces at the cellular scale, acoustic tweezers can be used to rotate and translate cells precisely as well as separate and pattern biological particles. 3 As the only single-sided transducer, a single beam acoustic tweezer can be applied to the skin with the manipulation inside the body.…”

“…Because of their fast response, wide bandwidth, and high sensitivity, increasing numbers of novel devices based on piezoelectric ultrasonic transducers have attracted people’s attention, including ultrasound imaging, therapeutic and surgical ultrasound including acoustic tweezers, , high intensity focused ultrasound, drug delivery, microfluidic channels, ultrasound-induced wireless energy transfer and communication, − etc. In personalized medicine, contact-free “microscopic handle” techniques require enhanced complex and precise operations with visualized edges, or small details of objects . Because of their ability to conduct complex manipulations and precisely measure forces at the cellular scale, acoustic tweezers can be used to rotate and translate cells precisely as well as separate and pattern biological particles .…”

Temperature‐Responsive Ultrasonic‐Wave Engineering Using Thermoresponsive Polymers

“…An ultrasonic wave (UW), which is defined as a sound wave with a frequency of more than 20 kHz, is inaudible to the human sensory system and harmless to human bodies, making it a low-cost, safe, and general-purpose candidate for diverse engineering applications. [1,2] UWs are widely utilized not only in the everyday lives of people but also in various application fields, including medical imaging, [3] in-display fingerprint sensors for smartphones, [4] nondestructive testing, [5] and sonar technology. [3] UWs propagating through solid media have a higher traveling speed than airborne UWs, resulting in distinctive features that can be used for various industrial application fields.…”