Fish could soon be delivering drugs to our body. At least, the newly developed robotic microscopic fish could. Manufactured by 3D printing technology, these microfish robots can swim, detect, and eliminate toxins from their environment.
The microfish are chemically powered and magnetically controlled
The microfish were developed by a team of nanoengineers at the University of California, San Diego. Smaller than the width of a human hair, these artificial microfish were so designed to perform complex tasks that traditional microrobots are incapable of meting out. By mimicking the biological structure of fish and miniaturizing it, they were able to incorporate propulsion, maneuvering and chemical sensing features into the bots.
They fabricated the fish from a hydrogel polymer using a precise 3D printing technology developed in their lab. The microfish were functionalized by loading the tail region of the fish with platinum nanoparticles and the head region with iron oxide nanoparticles. When fish are dunked in hydrogen peroxide, a chemical reaction between the peroxide and the platinum powers their propulsion. The iron oxide nanoparticles are subject to magnetic control. Therefore, these fish can be navigated using a magnet.
The microfish can detect and eliminate toxins
As a proof-of-concept experiment, the engineers loaded the microfish with nanoparticles imbued with polydiacetylene (PDA), which is a fluorescent chemical that can sense dangerous pore forming toxins such as those found in bee venom. The scientists believe that the swimming motion of microfish will aid cleanup of toxins. PDA has a unique property of emitting bright red fluorescence upon contact with toxins. Thus, the intensity of fluorescence on the microfish is an indicator of the detoxification of the medium. Microfish can therefore not only sense toxins, but also double up as detoxification systems.
How were the microfish printed?
The scientists used a rapid 3D printing technology called microscale continuous optical printing. This process allows them to print an array of hundreds of tiny microfish within seconds. This does not require the use of harsh chemicals, and because the technology is digitized, it can be adapted to various other biomimetic shapes like birds or sharks. Moreover, the nanoparticles could also be customized to endow the microfish with different functions. Their tiny size, easy customizability and rapid manufacture make these microrobots amenable to a plethora of biomedical applications like robotic microsurgeries and drug delivery.
Body Photo Credit: www.popsci.com