conducting links for charge transport. Small Van de Graaff generators are commonly used in science museums and science education to demonstrate the principles of static electricity. A popular demonstration is to have a person touch the high voltage terminal while standing on an insulated support; the high voltage charges the person's hair, causing the strands to stand out from the head. Others Not all electrostatic generators use the triboelectric effect or electrostatic induction. Electric charges can be generated by electric currents directly. Examples are ionizers and ESD guns. Applications Gridded ion thruster EWICON An electrostatic vaneless ion wind generator, the EWICON, has been developed by The School of Electrical Engineering, Mathematics and Computer Science at Delft University of Technology (TU Delft). Its stands near Mecanoo, an architecture firm. The main developers were Johan Smit and Dhiradj Djairam. Other than the wind, it has no moving parts. It is powered by the wind carrying away charged particles from its collector. The design suffers from poor efficiency. Dutch Windwheel The technology developed for EWICON has been reused in the Dutch Windwheel. Air ioniser Fringe science and devices These generators have been used, sometimes inappropriately and with some controversy, to support various fringe science investigations. In 1911, George Samuel Piggott received a patent for a compact double machine enclosed within a pressurized box for his experiments concerning radiotelegraphy and "antigravity". Much later (in the 1960s), a machine known as "Testatika" was built by German engineer, Paul Suisse Bauman, and promoted by a Swiss community, the Methernithans. Testatika is an electromagnetic generator based on the 1898 Pidgeon electrostatic machine, said to produce "free energy" available directly from the environment. See also Electrostatic motor Electrometer (also known as the "electroscope") Electret Static electricity References Further reading : Beschreibung unterschiedlicher Elektrizitätsverdoppler von einer neuen Einrichtung nebst einer Anzahl von Versuchen üb. verschiedene Gegenstände d. Elektrizitätslehre [Description of different electricity-doubler of a new device, along with a number of experiments on various subjects of electricity] Tübingen 1798. Wilhelm Holtz: the higher charge on insulating surfaces by side pull and the transfer of this principle to the construction of induction machines .. In: Johann Poggendorff, CG Barth (eds): Annals of physics and chemistry. 130, Leipzig 1867, p. 128 - 136 Wilhelm Holtz: The influence machine. In: F. Poske (Eds.): Annals of physics and chemistry. Julius Springer, Berlin 1904 (seventeenth year, the fourth issue). O. Lehmann: Dr. J. Frick's