Researchers flip how electrical signals move liquid droplets

When medical laboratories analyze blood samples for signs of disease, they sometimes use instruments that rely on a technology called digital microfluidics. The technique uses electric signals to pull tiny droplets of the sample across a surface so they can be analyzed. One drawback of the process is that the electric signals tend to damage the surface that the droplets travel over, which can cause the device to fail unexpectedly or deteriorate over time. Now, a research team led by UCLA engineers and scientists has demonstrated that digital microfluidic devices could be made much more durable if they use the electric signals to push, instead of pull, the droplets over the surface. A paper about The advance could lead to more powerful and reliable analytical tools for biochemical laboratories and environmental monitoring. It could also improve the durability of the liquid-based lenses used in devices like barcode readers and dental cameras. Those lenses can quickly adjust their focus because they contain a clear droplet that quickly adjusts its shape in response to electrical signals.