It’s alive!

At City University of Hong Kong’s Department of Biomedical Engineering, a recent innovation enables us to breathe life into inanimate objects that would otherwise be too awkward or brittle to reach a target site and carry out a desired task. We can actuate them.

actuation | /aktʃʊˈeɪʃ(ə)n/ | Learn to pronounce

noun: the action of causing a machine or device to operate.

“the automatic actuation of the cameras”

Agglutinate magnetic spray (abbreviated M-spray) consists of PVA, gluten, and iron particles; these combine to create a film approximately 100–250μm thick, which is thin enough to “preserve the target’s original size, morphology, and structure” and provide a means of actuating it using an applied magnetic field. In the paper (which includes visuals showing example shapes crawling, rolling, flapping their wings etc) the team goes into detail as to the precise compositions of spray tested, and precise dimensions & forces applied.

The concept of “doping” is important here in the initial formulation, which is then applied as paint to any physical surface. There is plenty of detail as to effects of viscosity and hydrophilics, with the discussion of strong Hydrogen bonds and van der Waals forces in how the spray spreads over the surface during application and “dries out” to remain stable (not dissolve into surrounding environments).

There is also a useful discussion of magnetic-induced disintegration, the technique by which, having completed its task, the sprayed millirobot can be destroyed safely.

How was the research funded?

Entirely by National Science Foundation of China and Hong Kong RGC General Research Fund.

Courtesy of Researcher, you can read the full paper for free using this link.

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