This week we were given a presentation by an engineer extraodinaire called Tom Vales, who showed us three relatively unknown devices; the Stirling Engine, the Peltier Device and the Mendocino Motor.

Stirling Engine:

A stirling engine is a heat engine operating on the continuous compression and expansion of a gas. The stirling engine is made up of a chamber that has a hot side heated by an external source and a cold side. Inside the chamber we can find the gas of choice(usually air, helium or hydrogen) and the displacer which is connected to a flywheel. Outside the chamber there is a piston andthe aforementioned flywheel that are also connected to each other. The way the stirling engine works is the following; Initially the displacer is at the bottom of the chamber. As heat is applied in the chamber, the kinetic energy of the molecules of the gas increases which means that in a fixed volume the pressure rises. The increase in pressure then moves the piston upwards. As the piston moves up the flywheel turns. The turning of the flywheel pushes the displacer downwards, thus moving the gas from the hot side to the cold side. As the gas reaches the cold side of the chamber the kinetic energy decreases and in extent the pressure in the chamber. This makes the piston move down, which makes the flywheel turn again(on the opposite direction this time). The flywheel again moves the displacer, but this time it moves it upwards, which transfers the gas to the hot part of the chamber and thus starting the circle all over again.The stirling engine is extremely quit and efficient which makes it very promising, especially if you consider the fact that they can be powered by any heat source. Despite this fact though, Stirling engines have not been used widely due to the cost in building one.(the sides of the chamber have to withstand heat and also the larger the chamber the more effective it is). In addition to this, it takes a while for the engine to start running or for it change its motion in any way, thus making the Stirling engine a good option in some occasions but not an alternative to internal combustion engines(for now at least).For the further information you can look at http://auto.howstuffworks.com/stirling-engine.htm and Ms. Kiki’s explanation of it:

Peltier Device:

The peltier device is a device that is based on the Peltier effect, which was discovered (surprisingly) by someone called Peltier. The Peltier effect of thermoelectric effect is the concept that when a current is applied on two dissimilar metals, one of them gets hot and the other gets cold. Also, the reverse version of this concept exists, which states that when a hot metal and another cold metal come into contact they create a current(this is called the Seebeck  effect found by someone called Seebeck). The effect of the peltier cooling is used in fridges where the cool side is put in the fridge to cool things inside it. A more detailed explanation of the effect can be found here: http://www.activecool.com/technotes/thermoelectric.html. Also, it has been noted that the Seebeck effect could be used for production of electrical energy, but that might be a little too impractical currently. One reason is that for the effect to generate a good amount of electricity the temperature gradient needs to be very big, which is usually hard to accomplish or too expensive. Of course the possibility of using earth’s resources could be a solution to this problem, if, for instance, we used the hot volcanoes and icy waters of the ocean. However, such a solution is too expensive and probably impossible(since i just thought about it). All in all, the peltier device is yet another cool device.

Mendocino Motor:

The mendocino motor is a device created in Mendocino california. Its premise is pretty simple. Light makes a rotor spin. Pretty simple huh? The more detailed explanation of the mendocino motor is the following; Light is cast on a rotor that has solar cells attached to it, which we know create an electric current. The rotor is built around a stick(anything can be used, even a pen). Also, the rotor has a magnet on it and is then put on the magnetic field of repulsing magnets to make it float(its magnet is repulsed my the other magnets, which makes it move away from them, that is upwards). Then, light is shed on the rotor, which produces an electric current due to the solar cells. The current produced then creates a magnetic field due to that weird electro-magnetic relationship, which makes the rotor turn to the next solar cell. Then, the process is repeated. Even though is device is sub-zero cool, it has not been able to be produced for various reasons.The primary reason for that is that we have not been able to take advantage of the rotating rotor due to the fact that it is floating, which means we have only been able to get very low power outputs. However, if this motor is utilized rightly it can provide a super electrical producer, since it could produce electrical energy from the solar cells(photovoltaic effect) and from the rotating rotor(mechanical to electrical energy).Further information on the mendocino motor can be found here: http://www.chessplayingrobot.com/id4.html. A video on the process of this device and how it was build can be found here(the video is made up of parts provided by none other than our very own Tom Vales):

Conclusion:

The three devices described above could be the future of humanity if we invest in them. They all have massive potential that we need to take advantage of. Then, we might stand a chance in this cruel world. The end of the world in 2012 might not even happen. Nah i am kidding. It will happen. Still these devices are cool so invest in them world, invest while you still can!