Forget batteries and solar panels – the American inventor came up with a flashlight, working from touch. A small device called Lumen is equipped with a panel that converts the heat of a person’s body into an electric current to power a small LED .

Lumen length of 4 centimeters and weighing 35 grams does not have a large light power, but the brightness is not inferior to the built-in flash smartphone, often used as a flashlight. The author of the development is the engineer Ross Zhuravsky from New York.

The device is equipped with a ceramic plate – a thermoelectric element, which is designed to collect heat energy from a person’s touch. Generation of electrical energy is due to the difference in temperature.


Reading the external temperature, Lumen “feels” when touched. The metal case of the flashlight accumulates the received heat.

On kraudfandingovoy site Kickstarter launched a campaign to raise funds for the implementation of the project, which has already managed to collect more than 40 thousand dollars from the declared 5 thousand. The campaign will last for another three weeks.

The temperature difference between the body and the environment is sufficient for the device to generate the energy needed to operate a single LED, “Zhuravsky said.

Lumen is able to produce about 15 mA and 3 volts with a relatively small temperature difference, Daily Mail writes.


The example on Kickstarter takes into account the air temperature difference (27 ° C) and the tip of the finger (36 ° C).

When the difference is large, excess energy is accumulated in the condenser. This energy is enough to supply a 5-millimeter LED with a light output of 3000 mCd, – explained the engineer.

Lumen is from 35 dollars. For an additional $ 15, a tritium backlight is available, making it easier to find a flashlight in the dark.

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