What if a building could stay cool simply because of its paint job? We’re not talking about putting flames on the sides. Purdue engineers have come up with a formulation of white paint that reflects the heat from sunlight and keeps surfaces cooler than their surroundings. Depending on the location, a building with this paint on the roof may not need air conditioning.
Radiative cooling paint is not a completely new animal, but the formulation developed at Purdue is quite impressive compared to commercially-available paints that only reflect 80-90% of sunlight.
Purdue’s paint reflects 95.5% of sunlight. It can keep surfaces up to 18°F cooler than their surroundings, even in direct sunlight. Where does the heat go? The paint radiates infrared heat, so it escapes the atmosphere and goes into deep space.
How does it do this? With abundantly available calcium carbonate fillers — the chalky stuff that antacids are made of. The paint absorbs next to no UV rays because of the wide band gaps in the atomic structure of calcium carbonate. Take a brief tour of this amazing paint after the break.
We wonder how many rooftops and roadways we’d have to paint with this stuff to have a chance at reversing climate change. It’s not terribly expensive to make, so the problem shifts to widespread education and adoption. What do you think?
Continue reading “Purdue’s Powerful Paint Could Cancel Climate Change”
Building a keyboard isn’t a big project these days. Controller chips and boards are readily available, switches are easy to find, and a 3D printer can do a lot of what used to be the hard parts. But engineers at Purdue have printed a self-powered Bluetooth keyboard on an ordinary sheet of paper. You can see videos of the keyboards at work below.
The keyboards work by coating paper with a highly fluorinated coating that repels water, oil, and dust. Special inks print triboelectric circuits so that pressing your finger on a particular part of the paper generates electricity. We were skeptical that the Bluetooth part is self-powered, although maybe it is possible if you have some very low-power electronics or you manage the power generated very carefully.
Continue reading “Paper Keyboard Is Self-Powered”
Purdue’s Bio-Robotics lab has been working on a robotic hummingbird and, as you can see in the videos below, have had a lot of success. What’s more, is they’ve shared that success on GitHub. If you want to make a flapping-winged robot, this is definitely where you start.
If you’ve ever watched a hummingbird, you know their flight capability is nothing short of spectacular. The Purdue robot flies in a similar fashion (although on a tether to get both power and control information) and relies on each wing having its own motor. The motors not only propel the wings but also act as sensors. For example, they can detect if a wing is damaged, has made contact with something, or has changed performance due to atmospheric conditions.
In addition to the tethered control system, the hummingbird requires a motion capture sensor external to itself and some machine learning. Researchers note that there is sufficient payload capacity to put batteries onboard and they would also need additional sensors to accomplish totally free flight. It is amazing when you realize that a real hummingbird manages all this with a little bitty brain.
The published code is in Python and is part of three presentations later this month at a technical conference (the IEEE International Conference on Robotics and Automation). If you don’t want to wait on the paper, there’s a post on IEEE Spectrum about the robotic beast, available now and that article contains preprint versions of the papers. The Python code does require a bit to run, so expect a significant flight computer.
The last hummingbird bot we saw was a spy. We’ve also seen robots that were like bees — sort of.
Continue reading “Robot Hummingbird Imitates Nature”