Electricity is pretty weird when you think about it. The fact that we can harness it allows us all the comforts we can imagine. Nearly everything in our lives uses electricity.
But there isn’t actually that many ways to make it do things for us. The toaster, the electric tea kettle, and a flashlight are all are using the same property. Ever noticed how your toaster glows when it’s on? Furthermore, most of these properties were discovered over 100 years ago.
One of my first jobs was working for Dean Kamen at DEKA Research. DEKA is a research facility. I constantly discussed physics with my team. They often bought cool toys and discussed the different properties of electricity. There happened to be some crazy new discoveries that year related to electricity as well.
If you are looking to make cool new things, looking at what electricity can do and is used for might spark some ideas.
The known causes of electricity
Electricity can cause a difference in temperature
This is called the Peltier effect. A Peltier device is literally a unit you can hook up to electricity and one side will be cold and the other side will be hot. The physics of this are kind of crazy. A circuit made of two different metals at two different temperatures creates a small amount of electricity because the electrons move at different speeds and it creates “voltage potential”.
This is how air conditioners work right? No, those actually use chemicals to quickly change air into a liquid and back with some magic that would require a separate post. The Peltier device is not very efficient at cooling things. A cheap mini cooler or mini air conditioner may use one, but otherwise there are better ways to cool things.
Also, a difference in temperature causes electricity
This is called the Seebeck Effect. That’s the great thing about all these properties, they are completely reversible to make other interesting things happen. A difference in heat can also be used the opposite way, to form electricity.
A difference in temperature powers a Stirling Engine.
They are pretty fun to watch. But this is actually a terrible example because it is using a difference in temperature to cause motion with air pressure. We want to form electricity.
A high school girl got in the news recently for patenting a flashlight powered by the Seebeck Effect. It would use the heat from your hand to power the light. I cannot believe I didn’t think of that.
Resistance in electricity gives off heat and light
I just said it, but I’ll say it again. Your toaster takes electricity and because it passes through a circuit with so much resistance, the electricity gives off lots of heat and light. Electricity moving anywhere has some amount of resistance. Your charging cable may get warm after awhile while using the computer, but add more resistance and you can have enough to boil your water and burn your toast.
Heat and light CANNOT cause electricity
Unfortunately, heat and light is simply a side effect of using electricity. It is not a property you can simply reverse without violating the second law of thermodynamics.
WHAT ABOUT SOLAR PANELS??? You might be shouting. The sunlight comes in and it produces electricity!
There is a tiny part of solar panels that converts the sunlight into heat first. The difference in temperature then creates the electricity, not the light. This is why solar panels are not as efficient when they get hot. Less electricity can be made if there is a smaller difference in temperature.
Pressure causes electricity
This is called the Piezoelectric Effect. If you put enough pressure on a crystal and you can produce electricity. There are a lot of random things that use this, but my absolute favorite is the rocket-propelled grenade launcher.
It makes sense not to rely on batteries or electricity in a war zone. There is also the added benefit of needing to push fairly hard with piezos. It will be hard enough that you do not accidentally shoot the grenade.
Also, electricity can cause pressure (well can make things expand)
This one surprised me when I found out. At DEKA, we had a tiny little box made out of a piezo material that you could not open. The box was sealed tight. The only way to open it was to apply a current to it so it expanded and could open. I could not find any current use cases for this property, I will have to look further.
A magnet moving perpendicular to conductive wire creates electricity
Ever seen the shake flash light informercials? If not, don’t worry. The product was discontinued long ago. The future of the Seebeck Effect Flashlight does not look good. The idea was you simply shake the flashlight a few times, the magnet passes between the conductive wires and its enough to have a little light.
Also, electricity can cause a magnet to move perpendicular to a conductive wire
Nearly everything cool you know is powered this way because this is an electric motor. Creating mechanical motion from electricity is powerful. Make doors open, make printers print, make cars drive (electric ones anyway), make robots, automate any motion you can dream up!
Once you have electricity creating motion in one direction, it is only a matter of some gears and mechanical engineering to create rotational motion or motion all directions.
Storing Electricity
Electricity can do some cool stuff, but what if we are not producing electricity at that moment? What if its dark out so our solar panels aren’t doing anything. Good thing a lot of smart men created a way to store electricity.
The most popular batteries use chemicals to store the energy. And then when we want to use the energy, we simply draw it back out. This is pretty much how the electrical grid works.
“Alternative” batteries are also an option. One start-up I heard about was using the electricity to raise giant cement blocks on strings. Then when the electricity is need it can use that potential energy from gravity and drop the blocks. It is more efficient than chemical storage. You could try anything really as long as it stores energy, compress air into tubes? It will just be difficult to do so on a mass scale.
The real weird stuff
When I was working at DEKA Research, some news came out about the weirder properties of electricity. We don’t fully understand them even to this day.
One you’ve seen a million times in the bath, but you never noticed. When bubbles pop, they can cause a small amount of light. This is called Sonoluminescence. They cause a really really small amount of light lasting a few hundred trillionths of a second.
Here is an even weirder one. Regular, ordinary, everyday tape in a vacuum causes light and X-Rays when you pull it. This is technically called triboluminescence at work.
Scientists created a completely mechanical X-Ray machine by making a device where they could continuously pull multiple scotch tape rolls at once.
For the most part, we really maxed out the mechanical motion part of electricity. I wonder what other small things we might discover or other products we can make with the other properties.
But also, what else is there? Battery-powered products, apps, and websites are the world’s focus now. If we didn’t find electricity what would we be focused on exactly? Is there something just as important than we have focused our efforts on yet?