Those who work in different spaces may have different definitions of the term “high voltage”. For someone working on the GPIO pins of a Raspberry Pi it might be as little as 5 volts, someone working on a Tesla coil might consider that to be around 20 kV, and an electrical line worker might not reference something as HV until 115 kV. What we could perhaps all agree on, though, is that getting 300 volts out of a USB power supply is certainly a “high voltage” we wouldn’t normally expect to see in that kind of context, but [Aylo6061] needed just such a power supply and was eventually able to create one.
In this case, the high voltages will eventually be used for electrophoresis or electrowetting. But before getting there, [Aylo6061] has built one of the safest looking circuits we’ve seen in recent memory. Every high voltage part is hidden behind double insulation, and there is complete isolation between the high and low voltage sides thanks to a flyback converter. This has the benefit of a floating ground which reduces the risk of accidental shock. This does cause some challenges though, as voltage sensing on the high side is difficult while maintaining isolation, so some clever tricks were implemented to maintain the correct target output voltage.
The control circuitry is based around an RP2040 chip and is impressive in its own right, with USB isolation for the data lines as well. Additionally the project code can be found at its GitHub page. Thanks to a part shortage, [Aylo6061] dedicated an entire core of the microprocessor to decoding digital data from the high voltage sensor circuitry. For something with a little less refinement, less safety, and a much higher voltage output, though, take a look at this power supply which tops its output voltage around 30 kV.
If you want to get into electronics, it’s pretty straightforward: read up a little, buy a breadboard and some parts, and go to town. Getting into molecular biology as a hobby, however, presents some challenges. The knowledge is all out there, true, but finding the equipment can be a problem, and what’s out there tends to be fiendishly expensive.
So many would-be biohackers end up making their own equipment, like this DIY gel electrophoresis rig. Electrophoresis sorts macromolecules like DNA or proteins by size using an electric field. For DNA, a slab of agarose gel is immersed in a buffer solution and a current through the tank moves the DNA through the gel. The shorter the DNA fragment, the easier it can wiggle through the pores in the gel, and the faster it migrates down the gel. [abizar]’s first attempt at a DIY gel rig involved a lot of plastic cutting and solvent welding, so he simplified the process by using the little plastic drawers from an old parts cabinet. With nichrome and platinum wires for electrodes for the modified ATX power supply, it’s just the right size and shape for the gel, which is cast in a separate mold. The video below shows the whole build, and while [abizar] doesn’t offer much detail on recipes or techniques, there are plenty of videos online to guide you.
Need more apparatus to deck out your lab? We’ve got you covered there too.
Continue reading “Get Into Biohacking On The Cheap With This Electrophoresis Rig”
The theme of this year’s Hackaday Prize is to build something that matters, and there is nothing more important than water quality and pollution. Everything we eat and drink is influenced by the water quality in rivers and reservoirs. C4Derpillar, a semifinalist for the Hackaday Prize, is solving the problems of water-related health issues with innovative sensors for under $500 USD per unit.
The C4Derpiller is using capillary electrophoresis (CE) to detect anions and cations in waterways. CE pulls a water sample through a very thin tube with an electric current. As water is moving through this capillary, a sensor is able to detect heavy metals, pesticides, and other pollutants in a water supply. The team behind C4Derpiller has written a few posts about the separation chemistry of their device
Commercial CE equipment costs tens of thousands of dollars. The team behind the C4Derpillar are hoping to develop their pollution monitoring device and make it available for about $500 USD. That’s cheap enough for multiple pollution monitoring stations in the third world, and by pushing the results to the cloud, the C4Derpillar will be able to monitor pollution in real time.
You can check out C4Derpillar’s Hackaday Prize video below.
Continue reading “Hackaday Prize Semifinalist: Water Quality Monitoring”