GaN-on-diamond semiconductor material that is stable to 1,000 C
The need for more powerful electronic devices in today's society is curtailed by our ability to produce highly conductive semiconductors that can withstand the harsh, high temperature fabrication processes of high-powered devices.
Gallium nitride (GaN)-on-diamond shows promise as a next-generation semiconductor material due to the wide band gap of both materials, allowing for high conductivity, and diamond's high thermal conductivity, positioning it as a superior heat-spreading substrate. There have been attempts at creating a GaN-on-diamond structure by combining the two components with some form of transition or adhesion layer, but in both cases the additional layer significantly interfered with diamond's thermal conductivity—defeating a key advantage of the GaN-diamond combination.
"There is thus a need for a technology that can directly integrate diamond and GaN," says Jianbo Liang, associate professor of the Graduate School of Engineering, Osaka City University (OCU), and first author of the study, "However, due to large differences in their crystal structures and lattice constants, direct diamond growth on GaN and vice versa is impossible."
A pair of Trilobites, fossils of marine arthropods that went extinct around 250 million years ago, are mounted on custom robotic platforms. The machines emulate the supposed behavior of the extinct animals and grant them a late second chance: They roam the floor, try to hide from bright light and chirp quietly from time to time.
Trilobite fossils, custom plastic parts, custom electronics, motors. 10 x 10 x 10 cm each. The robotic platforms are based on a design by Felix Fisgus.
Got distracted and I converted an old camera to full-spectrum, making good on this post.
It's an old Canon SX110 IS, mid-range point and shoot from around 2008. My main pocket camera is a descendant of this.
didn't get a lot of photos of the disassembly because i was hurrying a bit (which hurt me later, we'll get there) but disassembly was surprisingly smooth. A few adventures with supplying power to the lens motor just to get it to retract fully but nothing big. Managed to get the filter out with minimal fuss.
It's a tiny piece of dichroic glass that was sandwiched in the sensor assembly. Most cameras have at least one basic filter to cut out UV, IR or both.
Here's some comparison photos after removing it: It looks like these otherwise black mousepads are made of an IR reflecting material, glowing purple under ambient IR, which is different from the black powder-coat of the desk, which seems to absorb near-IR just as much as visible light. I wonder if that's so that modern infrared based mouse sensors can see better. Probably!
Reassembly was where things got messy: I didn't notice the motor control ribbon get disconnected and so I futzed around a while before I solved that, and putting that in involves removing the mainboard from the chassis. I forgot to plug the mainboard back into power when I reassembled it, and while jiggling some connections I tore through the ribbon cable that connects the shutter, power, and mode control group to the mainboard. Fuck ribbon cables, all my homies hate ribbon cables
Fortunately, I can still get the thing to power on by shorting some easily accessible bare copper on the board (which is how I got those verification shots), and the part that got damaged should be easy to replace: all I need is a donor camera. There's someone selling one on Marketplace for a reasonable price, and I'll put out a call on the local used tech forum as well.
Next steps would be finding some Visible, UV and IR filters so I can select particular regions of the spectrum, and probably a couple band-pass filters for looking at vegetation and so on. With an adequate filter setup (maybe I'll get a filter holder printed) and the CHDK firmware mod for this camera, I'll be able to stick it on a tripod and capture some of those dreamy snow-white foliage pics all the infrared photographers love so much.
This was a pretty finicky operation so all in all I'm pretty happy that I only broke one easily replaceable part. If I hadn't been able to get this powered on I probably wouldn't have been willing to put out the expense for a part replacement. Not bad for maybe an hour and a half's work.