By storing excess electrical energy that is generated by the dynamo in a capacitor, and getting the spring to unwind only when the capacitor charge falls below a certain threshold, it has proved possible to extend the playing time of the second-generation radio to about an hour.

ECONOMIST: Clockwork technology

The better the insulator, the more charge a capacitor can hold.

ECONOMIST: Combinatorial chemistry

Engineers had learned that a resistor, which restricts the flow of electrical current, is best made of certain materials and a capacitor, which stores electrical charge, of others.

ECONOMIST: Jack Kilby

As eardrum vibrations naturally create a usable voltage from brain signals, the prototype can build enough charge in a capacitor to drive a very low-power wireless transmitter that relays the electrochemical properties of the ear and potentially diagnoses balance or hearing problems.

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We're not exactly sure what makes these virus transistors so special, but apparently the transistors they've built out of the nano-coated strands, and sandwiched between two electrodes, are easy to switch between ON and OFF states, since they don't need to build up a charge at a lame-o capacitor before they can be switched.

ENGADGET: Platinum-coated virus to be used for speedy memory

The computer industry constantly strives to pack more, and therefore smaller, components on to each chip, but the smaller a capacitor gets, the harder it is to store enough charge on it.

ECONOMIST: Combinatorial chemistry

By using a capacitor instead, Mazda saves weight and space and, unlike a battery, it can charge and discharge instantly without deteriorating during prolonged use.

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