Engineers at the University of Sheffield have created microscopic rockets that may end up being used to deliver drugs inside the body. The rockets are only 300 microns long and made of silk scaffolding. They’re powered by enzymes in catalytic reactions with the liquid environment around the rocket, and can be adapted to move in a predefined trajectory.
These micro-rockets are produced using a 3D inkjet printer and carefully embedding the catalytic material allows the scientists to define how the propulsion is distributed, which in turn defines the trajectory of the rockets.
Being made out of silk, the rockets are biocompatible and don’t require to be covered in a catalyst to move through bioliquids with ease.
Here’s a video showing off one such micro-rocket:
Image caption: a) Schematic of the RIJ process for manufacturing catalytic micro-rockets. Stage 1: Alternate printing of a silk/catalase/PEG ink and a methanol ink (to transform printed silk ink from soluble random coils to insoluble beta-sheet structure) to build the catalytically active base of the micro-rocket. Stage 2: Ten layers of PMMA ink are deposited to act as a divider between the two halves of the rocket (to stop the penetration of oxygen bubbles generated into the inactive part of the micro-rocket). Stage 3: The second half of the rocket is deposited as in stage 1, but a silk/PEG ink is now used. Stage 4: Manufacture complete, substrate is immersed into the fluidic swimming media. Stage 5: Ultrasonication is used to detach the micro-rockets from the substrate. SEM images for micro-rockets: b) overview of silk rocket RIJ array, c) top view of a symmetrically active silk rocket, d) symmetrically active rocket, and e) Janus micro-rocket: red arrow indicates PMMA barrier layer between catalytically active and inactive segments; fluorescent microscopy images of FITC labeled catalase in micro-rockets: f) single ink micro-rocket (symmetrical) and g) Janus micro-rocket.
Study in journal Small: Reactive Inkjet Printing of Biocompatible Enzyme Powered Silk Micro-Rockets…
Source: University of Sheffield…