Technique utilises acoustic waves to sort cells on a chip

Penn State researchers have developed a technique that uses acoustic waves to sort cells on a chip, a development that could allow more cell types to be analysed simultaneously.

The device uses two beams of acoustic waves to act as acoustic tweezers and sort a continuous flow of cells on a dime-sized chip, said Tony Jun Huang, associate professor of engineering science and mechanics at Penn State. By changing the frequency of the acoustic waves, researchers can alter the paths of the cells.

In a statement, Huang said that since the device can sort cells into five or more channels, it will allow more cell types to be analysed simultaneously, which paves the way for smaller, more efficient and less expensive analytic devices.

‘Eventually, you could do analysis on a device about the size of a mobile phone,’ said Huang. ‘It’s very doable and we’re making in-roads to that right now.’

Biological, genetic and medical labs could use the device for various types of analysis, including blood and genetic testing, he added.


‘Today, cell sorting is done on bulky and very expensive devices,’ said Huang. ‘We want to minimise them so they are portable and inexpensive and can be powered by batteries.’


In addition to the inefficiency and the lack of controllability, current methods produce aerosols — gases that require extra safety precautions to handle.



The transducers are said to be tuneable, which allows researchers to adjust the frequencies and create pressure nodes on the chip.




Following this experiment, the researchers sorted human white blood cells that were affected by leukaemia. The leukaemia cells were first focused into the main channel and then separated into five channels.


‘We can do more,’ he said. ‘We could do 10 channels if we want; we just used five because we thought it was impressive enough to show that the concept worked.’