Monthly Archives: March 2016

Sustainable Evil


Meet Lil’ Beelzebub, the adorable doll that shoots beams of pure evil from its eyes when you rub its hair!! No batteries required!

The more serious proposal is to create a working triboelectric nanogenerator (TENG) using strips of teflon and acrylic film, and demonstrate the concept by mounting it as the “hair” of a doll and using the power harvested from it to light up the doll’s eyes. I intend to build on the research of Professor Zhong Lin Wang’s group at Georgia Tech, who have published a number of papers on different methods of generating, harvesting and storing triboelectric energy.

I’m hesitant to propose a specific bill of materials at this point, as at least half of this project will be experimentation before the final piece is assembled, but at a minimum it will involve:

teflon film

acrylic film

copper foil




As of right now, I have the teflon and acrylic films (as well as plenty of copper foil and a decent selection of capacitors) and am ready to begin experiments.  My first main concerns are establishing that the process works as I think it does, and secondarily, figuring out how to integrate the triboelectric surfaces with the electrodes. Then I will move on to harvesting and storage systems (paying special attention to the very high transient voltages that are likely to be generated) and finally construction of the doll itself. My goal is to have informed answers to the first two questions by next week, and then proceed based on that information.

Further reading on TENGs:

The Little Robot that Could (Burn Down the Building)


A robot that attempts to light a match!


The circuit is a Miller Solar Engine, employing a single 65mm solar panel, a TC54 voltage detector and 4700 uF and 10 uF capacitors to periodically fire a low-voltage motor and grind a match head on a striker held against it by a spring.

Total storage capacitance is 4700 uF; at the 3.16V triggering voltage of the circuit, the system is storing and then releasing 0.0235 joules of energy. The timing capacitor across the voltage detector has a capacitance of 10 uF.

(NB: out of an abundance of caution, we’re replacing the real match with a dummy match if/when our robot is put on display)