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Joined 1 year ago
Cake day: June 26th, 2023
  • thefartographer@lemm.eetoScience@beehaw.org•New nanogenerators offer 140x power density, could replace solar cells
    5·
    22 days ago

    Okay, I’m gonna try my best here, but first a disclosure:
    I am not a scientist nor engineer or whatever. I’ve been recognized and won some awards for a class I created teaching about solar panels to young kids, but this is with no formal background. I’m going to make some assumptions about the new technology being discussed, which could be wrong. I’m going to make some comparisons to photovoltaics, which could also be wrong. I’m trusting that the researchers who told me that I explained solar cells correctly weren’t lying to me.

    I apologize in advance if this comes off like an elia5, but that’s the youngest age I taught this shit to, so I’m just falling back into old habits.

    Solar cells, while relying on a lot of really cool molecular properties can be broken down into over-simplified kinetic mechanisms. Solar cells at their most basic three components are: a material which is relatively negatively charged, a material which is relatively positively charged, and a material that allows for the flow of electrons under the right conditions.

    Electrons are these tiny parts of the stuff that makes up everything. They’re like a dot in space, sometimes attached to atoms, sometimes just flying around looking for something to attach to. They’re negatively charged and try to find places or things that are more positively charged than themselves kinda like how the negative pole of a magnet tries to find the positive pole of a magnet.

    To make a solar cell generate electricity, you have to hit it with the right kind of light. Light is one of those tricky things that can exist as both a particle and a wave. Particles of light are photons, and photons are a lot like electrons in that they’re a dot in space, just flying around, looking to crash into stuff! Sometimes they crash into a surface, or bounce off and then crash into. your eyeballs and that’s how you see things.

    If you could imagine photons and electrons as steel marbles, you can imagine what would happen when a photon hits an electron: it can cause the electron to move! But electrons don’t really like to move unless they have somewhere to go. If you roll one marble at another, you’ll never get the second marble moving quicker than the first. But consider that the electron marbles don’t love being close to each other, just like when you hold the same poles of two magnets next to each other. So, when you hit your first negatively charged material with photons, you can get some electrons to fly off of it! Especially if you hit it hard enough.

    But if you put that negatively charged material inside of something that makes it a little bit harder for the electron to move, when it gets hit by a photon, it might move a little, but it won’t actually leave because moving is hard and it has nowhere to go. Now, if you add a relatively more positively charged material to this setup, any electrons that move a little have somewhere else to go! So, if you hit the electrons just hard enough, they’ll fly off the negative material and shoot at the positive material!

    What’s really cool is that because the electron is kinda stuck on the negative material, but attracted tot he positive material, you can actually get the electron to move with quite a bit more energy than you’d expect! Even cooler than that is if you have something near the materials that conducts electricity, like a wire, you can get the electron to hit other electrons in the positive material and that pushes a chain of electrons forward just hard enough that you generate a voltage!

    If you’d like to see this for yourself, here’s a really cool experiment you can do at home:

    1. Get some copper flashing and cut two pieces of it.
    2. One of the pieces, leave it just as it is. The other piece, heat it on an electric stove top at high temperature. I mean really heat it. Let it cook until it turns deeper red and even beyond that until it gains a black film. Keep going a little longer until some of the black film start to flake and jump off of the copper flashing. That black film means you’ve oxidized the copper and made it more negatively charaged than regular copper.
    3. Now, wash your oxidized copper with soap and water, trying to scrub off as much of the black film as possible without scrubbing off the red stuff underneath it.
    4. Fill a clear container with VERY salty water, then place each piece of copper on opposite ends of the container.
    5. Attach alligator clips jumper wires to the pieces of copper and read the voltage with a voltmeter. You’ll notice a very very small charge!
    6. Shine a really bright light on your setup and you should see the voltage go up a little. Try taking the setup outside into direct sunlight and see it go up a little more! Congratulations, you’ve made a rudimentary photovoltaic cell!

    Finally, let’s equate this to the new technology:
    On a dry day, try wearing socks and rubbing them on some carpet and then touch a doorknob—you should feel a shock! This is static electricity. Rubbing the socks on the ground builds up extra electrons in your body just like the negatively charged part of a solar panel. The doorknob is like the relatively positively charged part. The air is like the salt water or material that only lets electrons flow under the right conditions. In this instance, the right conditions are touching the negative and positive parts to each other. This is a very different setup, but similar concept to how photovoltaics works.

    It sounds like this new technology works like this but on a much smaller scale. Your movements causes part of the material to build up static electricity and become negatively charged. Once you’ve built up enough extra electrons and (I think) bend the technology in the right way to get the relatively positively charged side close to your static electricity side, the extra electrons jump from one material to the other, generating a charge!

    In a really really REALLY roundabout way, it’s all exactly the same as solar technology except that all the parts are different, there’s a different catalyst, your energy input and voltage differentials are completely different.

    You know what? It’s not similar at all, but I think I get what they’re going for.

  • thefartographer@lemm.eetoOpen Source@lemmy.ml•Open source e reader
    23·
    5 months ago

    You might be in a better position than you realize! I see two great options for you:

    Option 1.

    Here’s a new battery for your reader, it’s about $13.

    Here’s a battery replacement video. It’s amazingly simple! I forgot what wonderful times the aughts were for diy repair.

    Option 2

    If you’re feeling a little more carefree and like saying “damn the aesthetics!” Especially when you mention keeping readers out of landfills:

    Buy a broken eReader off of eBay that still turns on and scavenge the battery. Most of them seem to use the same voltage. If the battery you source doesn’t fit, make a notch in the side of your reader and tape the new battery to the back or whatever. Donate the remainder to your local Makerspace.

    If you end up enjoying your little rebellious repairs, buy bulk non-functioning eReaders and try using them to repair each other. Donate the functioning ones to your local library and the non-functioning parts to your local Makerspace.

  • thefartographer@lemm.eetoRPGMemes @ttrpg.network•This is the fun part
    2·
    10 months ago

    I guess for me in my last campaign, it was less that I was trying to be a jokester and more that actions which seemed somewhat reasonable to me and high-risk/high-reward were not welcomed by the rest of the group and I didn’t realize how serious people were going to be. We were playing in the world of Firefly and I tried hailing an approaching ship to see what they wanted and if I could negotiate.

    The fact that the DM was shocked should have been a hint that I was doing the wrong thing, but at the time I thought that I found a plot hole and was doing such a good job that the DM was blown away. I was wrong and my character has incapacitated by another member of the crew, which continued until I realized that I probably wasn’t welcome to continue campaigning with the group. When I realized this, I genuinely felt really bad that I’d probably upset the group, but it wasn’t until now that I realized how seriously people take this.

    I’ve never before played with the specific intent of keeping my character alive, but I think that was more of a videogame mentality. Other folks in the group aren’t exactly excited that I’m putting their characters lives on the line because people obviously invest real time and care into this. My realization was less that I joke too much and more that I don’t take things seriously enough.