State Key Lab of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
State Key Lab of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
Ultrasonics. 2020 Apr;103:106067. doi: 10.1016/j.ultras.2020.106067. Epub 2020 Jan 20.
Controlled capture of single biological micro particles, with effective capture function, little heat damage to and good stability of captured samples simultaneously, has been a technological challenge in the area of micro manipulation. This paper presents an ultrasonic tweezers based new strategy to meet the challenge. In the strategy, being different from the other ultrasonic methods, the MMP (micro manipulating probe), which vibrates elliptically, is in contact with the substrate. Single yeast cells with a diameter of 3-7 μm and Chlorella vulgaris powders with a diameter of 2-10 μm near the MMP can be sucked onto the MMP's tip. The captured particle can be transferred to a desired location at the interface between the water film and substrate by moving the ultrasonic tweezers. The temperature rise in the capture region is less than 0.1 °C, and the sucking distance can be up to 20 μm. The captured particle is in contact with the MMP's tip, which results in a good stability of the captured particle. The experiments also show that it is possible to use multiple MMPs to individually capture single cells. The finite element analyses indicate that acoustic radiation force generated by the ultrasonic field around the MMP is responsible for the capture. Moreover, the effects of the orthogonal vibration components, tilt angle and length of the MMP on the capture capability are clarified.
同时具有有效捕获功能、对捕获样品的热损伤小和稳定性好的单个生物微粒子的控制捕获，一直是微操作领域的一项技术挑战。本文提出了一种基于超声镊子的新策略来应对这一挑战。在该策略中，与其他超声方法不同，微操作探针（MMP）以椭圆形振动并与基底接触。直径为 3-7 μm 的单个酵母细胞和直径为 2-10 μm 的普通小球藻粉末可以被吸到 MMP 的尖端。通过移动超声镊子，可以将捕获的颗粒转移到水膜和基底之间的所需位置。捕获区域的温升小于 0.1°C，抽吸距离可达 20 μm。捕获的颗粒与 MMP 的尖端接触，这导致捕获颗粒具有良好的稳定性。实验还表明，使用多个 MMP 可以单独捕获单个细胞。有限元分析表明，MMP 周围超声场产生的声辐射力是捕获的原因。此外，还阐明了 MMP 的正交振动分量、倾斜角度和长度对捕获能力的影响。
