Nanoengineers at the University of California, San Diego, have utilised innovative 3D-printing technology to manufacture fish-shaped microrobots — dubbed microfish — that may one day be used in detoxification, targeted drug delivery, or even surgery.
The microfish are a significant advancement in microrobotics.
While most existing microrobots are incapable of carrying out sophisticated tasks – largely due to the their simplistic structures – microfish are a new breed.
The UC San Diego research team behind the microfish designed a new 3D-printing method to make manufacture of the microrobots simpler and to allow for more complex designs.
According to a report in EurekAlert, microscale continuous optical printing (μCOP) allows for “speed, scalability, precision and flexibility”, enabling researchers to print hundreds of microfish – each smaller than the width of a single human hair – in seconds.
The method centres on a digital micromirror array device (DMD). Each micromirror in the DMD can be positioned individually, allowing researchers to project UV light in a very specific pattern onto photosensitive materials that solidify on exposure to UV rays.
The microfish were constructed in this way and built up layer by layer. This meant that different sets of “functional nanoparticles” could be printed into different parts of the microfish’s body.
In this way, researchers were able to create microrobots that could ‘swim’ through hydrogen peroxide – platinum in the tail reacts with the chemical to propel the bots forward – and be directed using magnets.
During the course of this proof-of-concept research, the team at UC San Diego – led by Prof Shaochen Chen and Prof Joseph Wang – incorporated toxin-neutralising nanoparticles in the microfish.
Polydiacetylene (PDA) nanoparticles were infused with the microfish. These nanoparticles capture toxins that can be found in bee venom. They also glow when they come in contact with toxin molecules.
Researchers were able to monitor the detoxification ability of the bots by monitoring that glow.
They found that the powerful swimming of the microfish significantly enhanced their ability to clean up toxins.
Of course, the applications of this technology could be far-reaching.
“Another exciting possibility we could explore is to encapsulate medicines inside the microfish and use them for directed drug delivery,” said Jinxing Li, a co-author of the study.
“[μCOP] has made it easier for us to test different designs for these microbots and to test different nanoparticles to insert new functional elements into these tiny structures,” continued Li. “It’s my personal hope to further this research to eventually develop surgical microbots that operate safer and with more precision.”
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