Manipulating individual cells and microscopic particles may be extremely valuable for testing new therapies, targeting tumors, and for studying the underlying causes of disease, but it is very difficult to directly manipulate individual cells within an environment shared with other cells.
A collaboration of researchers from University of California San Diego, University of Pennsylvania, and Harbin Institute of Technology in China has developed pretty amazing microscopic devices that can move in 3D and push living cells and other similar sized particles around with unprecedented ease and precision.
The devices are hollow polymer capsules coated with gold and containing a speck of magnetic nickel (normally non-ferrous). The nickel is used to tug on the microdevice through an external magnetic field.
Controlling a magnetic field to move individual cells is very hard, so in this case it is used to set the direction of these microswimmers. The actual power results from the fact that these devices are hollow and have a hydrophobic interior. An air bubble forms on the inside, and this air bubble can be targeted with ultrasound to propel the devices in all directions.
Here’s a set of fun short videos showing how the microswimmers are used to move cells and microparticles within a solution:
Open access study in journal Science Advances: 3D steerable, acoustically powered microswimmers for single-particle manipulation
Via: UC San Diego