Daniel Eindhoven build a usb powered Teslacoil able to produce small sparks. The coil of the device is printed on the board!
A new and improved PCB spiral Teslacoil. This Teslacoil has etched windings on a print circuit board. It has a USB interface which also powers the coil. The resonance frequency is about 4MHz. It has a turns ratio of 1:160 with 6mil tracks for the secondary. The total trace length of the secondary is 25m.
USB powered – PCB TeslaCoil – [Link]