A professor at Suffolk came into my science class recently and did a guest presentation on different ways in which electricity can be produced.  He had multiple devices going on in the class room to show this, two of the more notable ones were the Mendocino motor and the Peletier Junction. These devices both use more unusual ways to create electricity yet exemplified more creative ways to create power without releasing green house gases.

The Mendocino motor consists of a multi-sided rotor block in the middle of a shaft. The rotor block has two sets of wingdings and a solar cell attached to each side. The shaft is positioned horizontally and has a magnet at each end. The magnets on the shaft provide levitation by repelling magnets in a base under the motor. There is an additional magnet that sits under the rotor block and provides a magnetic field for the rotor. When light strikes one of the solar cells, it generates an electric current thus energizing one of the rotor windings. This produces a magnetic field which interacts with the field of the magnet under the rotor. This interaction causes the rotor to turn. As the rotor rotates, the next solar cell moves into the light and energizes the second winding, creating a current in an opposite direction to the first thus maintaining the rotation. This process repeats as the motor spins.

The Peletier Junction was showed to the class in hopes to teach us that, when a current is made to flow through a junction between two conductors A and B, heat may be generated.  Though, it is important to note that the heat generated at the junction is not determined by the Peltier effect alone, as it may also be influenced by Joule heating and thermal gradient effects.  This produces thermoelectric effect which is the direct conversion of temperature differences to voltage and vice versa. The Peletier Junction device creates voltage when there is a different temperature on each side. Interestingly when a voltage is applied to it, it creates a temperature difference.