Session: Research Posters

Paper Number: 118984

118984 - A Non-Invasive, Label-Free Acoustic Microfluidics Separation Device: An Experimental Study 

In this study, we investigated a microfluidics system that employs surface acoustic waves to separate micron-sized particles based on their size. Particle separation plays a crucial role in numerous biomedical applications such as HIV diagnosis, tumor cell isolation, and blood cleansing. The microfluidics device is fabricated on lithium niobate, which is a lead-free piezoelectric substrate with a high coupling coefficient.  Electrodes were patterned on the substrate forming the interdigitated transducers (IDTs). As the IDT pair generates the surface acoustic waves which propagate toward each other, pressure nodes and anti-nodes are formed inside the microfluidic channel. The microfluidics channel is created using polydimethylsiloxane (PDMS) which is a silicon-based elastomer and is bonded between IDT pairs. The mixture of base and curing agent component of Slygard 184 Kit has a ratio of 10:1. In the microchannel, there are two stages. During the first stage, the particles become aligned. In the second stage, the larger particles are separated from the smaller ones because they are exposed to a greater acoustic force, by design. The fact that the acoustic force is proportional to the particle volume leads to the size based separation capability of the microfluidic device studied. It should be highlighted that throughout this process, there is no utilization of external sheath flow, which is a typical method for separation. This device solves the issues associated with sheath flow, such as the possibility of reaction with particles, complicated design. We were able to demonstrate the separation capability via a solution containing a mixture of 3 µm and 10 µm polystyrene particles. Furthermore, additional experiments were conducted using 3 µm and 5 µm particles to demonstrate enhanced separation capability of the devices fabricated. The experiment parameters that were studied include input power, flow rate and particle concentration. In order to visualize the separation, fluorescence microscopy observations involved capturing images from both center outlet and side outlets of the channel. The particles on these images were analyzed by using Image J and the process called a watershed segmentation was applied in order to achieve more reliable results. We calculated the separation efficiency for two different sized particles in each experiment using the florescence microscopy-based setup. In summary, this technique involves using sound waves to manipulate particles or biological samples without any physical contact, making it non-invasive and label-free. It also does not cause any damage, making it highly beneficial for a wide variety of biomedical applications.

Presenting Author: Rasim Guldiken University of South Florida

Presenting Author Biography: Dr. Guldiken is a Professor and Associate Dean for Academic Affairs at University of South Florida

Authors:

Ozge Uyanik University of South Florida
Rasim Guldiken University of South Florida