Water is sometimes known as the universal solvent. But researchers at Harvard want to use water to put things together instead of taking them apart. Really small things. In the video below, you can see a simple 3D-printed machine that braids microscopic fibers.
The key appears to be surface tension and capillary action. A capillary machine uses channels that repel floating objects. By moving the channel, materials move to avoid the channel, and by shaping the channel, various manipulations can occur, including braiding. This is one of those things that is easier to understand when you see it, so if it doesn’t make sense, watch the video below. The example uses tiny Kevlar fibers.
Like all micro-machining techniques, there are a number of possible applications. The one mentioned in the paper is braiding antennas for better microwave frequency antennas.
This technique is interesting because no laser is required. According to the paper, the channels are nothing a common 3D printer can’t handle. Lasers are what we usually see. But with this technique, a 3D printer, a tank of water, some tiny fibers, and some slightly larger floats are all that is required.