LED mounted in a contact lens for possible virtual / augmented reality displays

Every so often, internet news aggregator sites run a story about a research group that put an LED into a contact lens, then inserted it into a rabbit's eye. I figured that I would try the same thing, but put the lens into my own eye. I accomplished this by laminating a coil of wire and an 0402 surface-mount LED between two ordinary soft contact lenses. I was hoping the lenses would stick to each other, but they did not, so I ended up fixing the edges together by pinching the plastic together with hot tweezers. This held well enough to capture a minute of video with the LED illuminated in my eye. For video purposes, I mounted the LED facing outward. An actual VR/AR display would have the LED facing inward.

I powered the LED by using a very primitive spark-gap transmitter built from a mechanical relay to send RF energy into a larger coil held near my eye. The large coil coupled the energy into the contact lens coil and pulsed the LED.

http://nextbigfuture.com/2011/11/single-pixel-contact-lens-display.html


http://www.cs.uic.edu/~kenyon/Papers/Soft%20Contact%20Search%20Coil.Vision%20Research.Kenyon.pdf

Improved stainless welds with large gas lens

My new TIG parts just arrived today, and I had to do a quick test. In short, the large gas lens makes a huge difference. Take a look at this beast: #12 cup with "large gas lens" and 1/16 tungsten


I am using the same exact 1/16" thick SS304 sheet metal that I have been practicing with all along:

Compare that weld bead to the pair of beads in my previous post. All settings are exactly the same except for the gas lens. Well, I guess I was using .040" tungsten in the previous post, but that should have helped if anything.


Here's a few more. I've heard that "salmon color" is the best thing a stainless welder can hope for. I changed the flow rate from 10 to 20 CFH going from top to bottom -- not much difference. The bottom bead had a longer post-flow, so the tail of the bead has less purple/blue.

The backsides of these welds are pretty messed up. I'll report about the Solar flux later.