If you have a project in mind that requires some sort of gesture input or precise movements, it might become a nettlesome problem to tackle. Fear this obstacle no longer: a team from the Wyss Institute for Biologically Inspired Engineering at Harvard have designed a novel way to make wearable sensors that can stretch and contort with the body’s natural movements.
The way they work is ingenious. Layers of silicone are sandwiched between two lengths of silver-plated conductive fabric forming — by some approximation — a capacitance sensor. While the total surface area doesn’t change when the sensor is stretched — how capacitance sensors normally work — it does bring the two layers of fabric closer together, changing the capacitance of the band in a proportional and measurable way, with the silicone pulling the sensor back into its original shape as tension relaxes. Wires can be attached to each end of the band with adhesive and a square of thermal film, making an ideal sensor to detect the subtlest of muscle movements.
Continue reading “A Flexible Sensor That Moves With You”
Published only 3 days before our article on how it is high time for direct metal 3D printers, the folks at Harvard have mastered 3D metal printing in midair with no support (as well as time travel apparently). Because it hardens so quickly, support isn’t necessary, and curves, sharp angles, and sophisticated shapes are possible.
The material is silver nanoparticles extruded out of a nozzle, and shortly after leaving it is blasted with a carefully programmed laser that solidifies the material. The trick is that the laser can’t focus on the tip of the nozzle or else heat transfer would solidify the ink inside the nozzle and clog it. In the video you can see the flash from the laser following slightly behind. The extrusion diameter is thinner than a hair, so don’t expect to be building large structures with this yet.
If you want big metal 3D printing, you should probably stick to the welders attached to robotic arms.
Continue reading “3D Printing Metal in Mid Air”
What if there was a job where you built, serviced, and prepared science demonstrations? This means showing off everything from principles of physics, to electronic theory, to chemistry and biology. Would you grab onto that job with both hands and never let go? That was my reaction when I met [Dan Rosenberg] who is a Science Lecture Demonstrator at Harvard University. He gave me a tour of the Science Center, as well as a behind the scenes look at some of the apparatus he works with and has built.
Continue reading “Demonstrating Science at Harvard University”
[Jennifer Lewis] is a Harvard Materials Scientist, and she’s recently come up with a type of Lithium Ion “Ink” that allows her to 3D print battery cells.
You might remember our recent 3D Printering article on Pastestruders, but this research certainly takes it up a few notches. The ink is made up of nano-particles of Lithium Titanium in a solution of de-ionized water and ethylene glycol. When producing the ink, small ceramic balls are added to the mixture to help break up microscopic clumps of said particles. The mixture is then spun for 24 hours, after which the larger particles and ceramic balls are removed using a series of filters. The resulting ink is a solid when unperturbed, but flows under extreme pressures!
This means a conventional 3D printer can be used, with only the addition of a high pressure dispenser unit. We guess we can’t call it a hot-end any more… The ink is forced out of a syringe tip as small as 1 micrometer across, allowing for extremely precise patterning. In her applications she uses a set up with many nozzles, allowing for the mass printing of the anodes and cathodes in a huge array. While still in the research phase, her micro-scale battery architectures can be as small as a square millimeter, but apparently compete with industry batteries that are much larger.
And here’s the exciting part:
Although she says the initial plan is to provide tools for manufacturers, she may eventually produce a low-end printer for hobbyists.
3D Printable electronics. The future is coming!