Skip to main content

Digital acoustofluidics to handle contactless and programmable fluids

Penelitian - Scientists explain in Nature Communications on a new digital microfluidics platform that uses sound waves and oil to avoid contamination for reusable lab-on-a-chip devices.

The Duke University researchers developed a way to manipulate, divide and mix biological fluid droplets to surf over acoustic waves in oil. This new technology forms the basis of rewritable and programmable biomedical chips that are completely reusable for different purposes from diagnostics to laboratory-based research.

Penelitian Digital acoustofluidics to handle contactless and programmable fluids

Automatic fluid handling has encouraged the development of many scientific fields including the robotic pipette system that revolutionized sequencing, clinical diagnostics and large-scale compound screening, but the system is large, expensive and does not handle small fluid volumes well.

The lab-on-a-chip system is able to fill this space to some extent, but is largely hindered by one major drawback is surface absorption. This device relies on solid surfaces and transported samples will leave traces that can cause contamination.

"There are a lot of liquids that contain certain proteins and reagents that tend to stick to chips, especially for biological samples like blood samples, sputum and feces," said Tony Jun Huang of Duke University.

The new lab-on-a-chip platform uses a thin layer of inert oil to stop droplets from the trace. Just below the oil, a series of piezoelectric transducers vibrate when electricity passes through it. This vibration creates sound waves in the thin oil layer above it.

The researchers created a vertical vortex that forms a small dimple in oil to both sides of the active transducer. The dimple holds droplets with volumes ranging from one nanoliter to 100 microliters along the oil surface as sound waves are modulated and different transducers are activated.

"The non-contact liquid handling mechanism inherently removes cross-contamination associated with surface adsorption and the need for surface modification.This allows reusable paths for drip to be dynamically processed on arbitrary routes without cross-talk between each other," says Huang.

Journal : Steven Peiran Zhang et al. Digital acoustofluidics enables contactless and programmable liquid handling, Nature Communications, 26 July 2018, DOI:10.1038/s41467-018-05297-z