Yu Nanxin, Geng Wenping, Liu Yukai, Zhang Huiyi, Lu Hao, Duan Zhigang, Yang Lingxiao, Zhang Yichi, Chou Xiujian
Key Laboratory of National Defense Science and Technology On Electronic Measurement, School of Semiconductor and Physics, North University of China, Taiyuan, 030051, China.
Key Laboratory of National Defense Science and Technology On Electronic Measurement, School of Instrument and Electronics, North University of China, Taiyuan, 030051, China.
Anal Bioanal Chem. 2024 Jan;416(2):509-518. doi: 10.1007/s00216-023-05058-y. Epub 2023 Nov 22.
The application of standing surface acoustic wave (SSAW) tweezers based on backpropagation superposition to achieve precise behavior manipulation of microscale cells and even nanoscale bacteria has been widely studied and industrialized. However, the structure requires multiple transducer components or full channel resonance. It is very challenging to design a simple structure for nano-control by complex acoustic field. In this study, a reflector-interdigital transducer (R-IDT) acoustofluidic device based on unilateral coherence enhancement is proposed to achieve SSAW definition features of periodic particle capture positions. The SAW device based on a unilateral transducer can not only generate leaky-SAW in water-filled microchannel, but also have a contribution of spherical waves in the vibration area of the substrate-liquid interface due to the Huygens-Fresnel diffractive principle. Both of them form a robust time-averaged spatial periodicity in the pressure potential gradient, accurately predicting the lateral spacing of these positions through acoustic patterning methods. Furthermore, a reflector based on Bragg-reflection is used to suppress backward transmitted SAW and enhance forward conducted SAW beams. By using a finite element model, R-IDT structure's amplitude enhances 60.78% compared to single IDT structure. The particle manipulation range of the diffractive acoustic field greatly improves, verified by experimental polystyrene microspheres. Besides, biocompatibility is conformed through red blood cells and Bacillus subtilis. We investigate the overall shift of periodic pressure field that can still occur when the phase changes. This work provides a simpler and low-cost solution for the application of acoustic tweezer in biological cell culture and filtering.
基于反向传播叠加的驻波表面声波（SSAW）镊子在实现对微尺度细胞甚至纳米尺度细菌的精确行为操纵方面的应用已得到广泛研究并实现产业化。然而，该结构需要多个换能器组件或全通道共振。通过复杂声场设计用于纳米控制的简单结构极具挑战性。在本研究中，提出了一种基于单边相干增强的反射器 - 叉指换能器（R - IDT）声流控装置，以实现周期性粒子捕获位置的SSAW定义特征。基于单边换能器的声表面波装置不仅可以在充满水的微通道中产生泄漏声表面波，而且由于惠更斯 - 菲涅耳衍射原理，在基底 - 液体界面的振动区域还具有球面波的贡献。它们两者在压力势梯度中形成强大的时间平均空间周期性，通过声学图案化方法准确预测这些位置的横向间距。此外，基于布拉格反射的反射器用于抑制向后传输的声表面波并增强向前传播的声表面波束。通过使用有限元模型，与单叉指换能器结构相比，R - IDT结构的振幅增强了60.78％。衍射声场的粒子操纵范围大大提高，经实验聚苯乙烯微球验证。此外，通过红细胞和枯草芽孢杆菌证实了生物相容性。我们研究了相位变化时仍可能发生的周期性压力场的整体偏移。这项工作为声镊子在生物细胞培养和过滤中的应用提供了一种更简单且低成本的解决方案。
