We know we aren’t supposed to eat a lot of sugar, but we still have ice cream. We also know we probably shouldn’t be inhaling solder smoke and 3D printer fumes, but we do that too. Not [Mike Buss]. His 3D printer has a major exhaust system.
We can sympathize with his process. He mentions he started out just wanting a fan running with some filters. Then he decided to add a way to turn the fan on and off when printing. Then he added sensors to detect fumes and fire. Data collection was almost an afterhthought.
Continue reading “3D Printing Air Filter System Does A Lot”
We are all intimate with face coverings to slow the spread of the coronavirus. Some are reusable, and some become waste after one use. [Dr. Ye Ruquan] and a research team from City University of Hong Kong, CityU, are developing an inexpensive reusable mask with outstanding antibacterial properties, and, get this, the graphene it contains will generate a tiny current when moistened by human breath. There isn’t enough power to charge your phone or anything, but that voltage drops as the masks get dirty, so it can help determine when it needs cleaning. The video after the break shows the voltage test, and it reminds us of those batteries.
All the remarkable qualities of this mask come from laser-induced graphene. The lab is producing LIG by lasering polyimide film with a commercial CO2 infrared model. In a speed test, the process can convert 100cm² in ninety seconds, so the masks can be made more cheaply than an N95 version with that melt-blown layer that is none too good for the earth. Testing the antibacterial properties against activated carbon fiber and blown masks showed approximately 80% of the bacteria is inert after 8 hours compared to the others in the single digits. If you put them in the sun for 10 minutes, blown fabric goes to over 85%, but the graphene is 99.998%, which means that one bacteria in 50K survives. The exact mechanism isn’t known, but [Dr. Ye] thinks it may have something to do with graphene’s sharp edges and hydrophobic quality. A couple of coronavirus species were also affected, and the species that causes COVID-19 will be tested this year.
An overly damp mask is nothing to sneeze at, so keep yourself in check and keep yourself fabulous.
Continue reading “A Graphene Mouth Screen”