Application Cases

Experiment Name: Surface Acoustic Wave Microfluidic Chip Particle Sorting Experiment

Research Direction: Surface Acoustic Wave Microfluidic Chips

Experiment Content: A sine wave signal generated by a signal generator is amplified through a power amplifier and loaded onto a lithium niobate substrate sputtered with interdigital electrodes, exciting the generation of surface acoustic waves. These waves produce different magnitudes of acoustic radiation forces on particles in the flow, causing different particles to experience varying changes in their motion states, thereby enabling the directional sorting of particles of different sizes. In this experiment, traveling surface acoustic waves were successfully used to sort 20μm, 30μm, and 50μm polystyrene microspheres from mixtures of (5, 10, 20μm), (5, 10, 30μm), and (5, 10, 50μm) polystyrene microspheres.

Testing Equipment: Signal generator, ATA-1200C broadband power amplifier, oscilloscope, precision syringe pump, microscope, etc.

Experiment Process: A sine signal generated by the signal generator is amplified through the power amplifier and loaded onto the interdigital electrodes to produce the piezoelectric effect, generating surface acoustic waves on the lithium niobate surface. Mixed particles are injected into the microfluidic chip using a precision syringe pump. After particle focusing is completed, the power amplifier is turned on to generate traveling surface acoustic waves. The particle sorting results are observed, and particles are collected at the target outlet for the calculation of sorting efficiency and purity.

Figure 1: Schematic Diagram of the Experimental Setup

Experimental Results: The sine wave signal amplified by the power amplifier is loaded onto a lithium niobate substrate with tilted interdigital electrodes, exciting the generation of traveling surface acoustic waves on the lithium niobate surface. The wavelength of the traveling surface acoustic wave is related to the electrode size, the frequency is related to the input frequency, and the amplitude is related to the input voltage. After determining the device's operating frequency range of 20MHz-40MHz, the acoustic radiation force coefficients for 20μm, 30μm, and 50μm particles were calculated. Signals at 35.84MHz, 34MHz, and 28MHz with a voltage of 15Vpp were selected for sorting. Ultimately, the sorting of the three types of particles was achieved, with sorting efficiency and purity both exceeding 96%.

Power Amplifier Recommendation: ATA-1200C

Figure: ATA-1200C Broadband Amplifier Specification Parameters