MIT 3D Prints With Glass
An anonymous reader writes: MIT's Mediated Matter Group has published a paper and a video about their new technique for 3D printing with glass. The top part of their printer is a kiln that heats the glass to temperatures of approximately 1900 degrees Fahrenheit, causing it to melt. The molten glass is then passed through an alumina-zircon-silica nozzle, which moves just like an extruder on normal 3D printers. "The frame of the printer is constructed out of 80/20 aluminum stock and square steel tube. They used three independent stepper motors and a lead screw gantry system and drivers which were controlled via an Arduino and a RAMPS 1.4 Arduino shield." The device's makers say, "The tunability enabled by geometrical and optical variation driven by form, transparency and color variation can drive; limit or control light transmission, reflection and refraction, and therefore carries significant implications for all things glass."
Mixing multiple types of glass within a single piece is crucial to making apochromatic lenses. If a fourth wavelength has to hit the same focal plane accurately, it gets much trickier, but can still be done under some conditions. The primary problem is getting glass with the right refractive index in the right place. The better this can be controlled, the more consistent the results will be. It's also more important as the maximum aperture increases, both because of larger lens elements and shorter depth of field.
I'm looking forward to this finding its way into camera lenses, which I would imagine is one of the primary design goals. it could bring what are currently $2500 f/2.8 "L" lenses within reach of the people who opt for f/4 and f/5.6 due to cost. (Unfortunately, there's nothing to be done about size and weight. If you want to gather light, you need lots of glass.)
How is the Riemann zeta function like Trump rallies? Both have an endless number of trivial zeros.