Blobs of water encased in nanoparticles can be carved into precise shapes with a laser, and even turned into a kind of miniature lab device.
When water is added to a gel of hydrophobic silicon dioxide nanoparticles, it naturally forms a pancake-shaped blob. at Xi鈥檃n Jiaotong University in China and her colleagues have discovered that these blobs can be carved into extremely precise shapes using a high-powered laser. These shapes maintain their form after cutting.
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The technique can be used to create a kind of microfluidic chip. These are normally made from solid surfaces with tiny channels for liquids to flow through. They are used for a wide variety of applications from disease testing to protein analysis, sometimes in devices described as a lab-on-a-chip.
Li and her colleagues showed that chips made from water can also contain channels where liquids can be mixed and reacted together, which might be useful for tasks like making hydrogels or detecting molecules. To demonstrate this, they carved out a well in a water chip for a sample with three attached testing compartments where they could identify the presence of protein and urea, as well as determine the pH.
The researchers also showed that such chips could be used to test drugs on cells. They created one with a compartment containing breast cancer cells and exposed them to a chemotherapy drug released from three channels.
These solid-free versions may overcome some limitations of ordinary microfluidic chips, such as unwanted forces and bubbles that can occur at the edges of the channels.
鈥淚n the future, maybe people can use this kind of strategy for biological and chemical synthesis, cell cultures or even do biomedical detection for RNA or DNA,鈥� says Li.
鈥淚t looks very, very simple, but it鈥檚 unusual at the same time,鈥� says at the University of Reading, UK. 鈥淚t gives slightly new properties, which is interesting.鈥� However, the technique needs to be developed further before it can produce useful devices, he says.
Nature Communications
