Electrostatic pressure on a charged body
ESP v1.0
by Jean-Louis Naudin
created on January 20, 2002 - JLN Labs - Last update February 3, 2002
All informations in this page are published free and are intended for private/educational purposes and not for commercial applications

The purpose of this experiment is to check if an asymmetrically shaped and charged body is able to produce a thrust itself along one of its axis. This thust is produced by an asymmetrical electrostatic pressure Vs the external referential (the Universe), this is the so called "Expansion Force" by Jean- Claude Lafforgue in his patent FR 2651388.

Experiment #1 :

Tested apparatus description :

I have built a body fully covered by an aluminum sheet, so that the E-Field inside is equal to zero. This is a cylinder with an ogival shape at one of its extremities while the other is flat. This conductive body, the ESP v1.0, is placed on plastic cylinder base ( 200 mm ) so as to be fully isolated from the beam balance which serves to measure the upward force. A +30KV DC power supply is connected to the ESP through a thin copper wire. If an asymmetrical electrostatic pressure is produced due the special shape of the ESP, it is possible to observe a resulting force along its main axis. To check this fact, the ESP has been placed on a beam balance and two tests have been conducted for checking the resulting thrust along its two axles ( horizontal and vertical ) while it is charged through a High Voltage power supply.

The ESP v1.0 specifications
  • The conductive body :
    - Fully covered by an aluminum sheet, 12/100 mm thick

  • Size : cylinder part : 175mm height, 100 mm diam - ogival part : 90 mm height, 100 mm diam

  • ESP v1.0 weight : 102 g

  • HV Power supply : +/- 30 KV DC, current 3 uA

TESTS RESULTS with a cylindrical conductive body :

When the ESP v1.0 is layed on its side ( symmetrical electrostatic pressure setup ), is charged with the +30 KV DC, there is no measurable thrust upward.

TESTS RESULTS with a spherical conductive body :

I have also conducted the test with a spherical conductive body. When the pherical conductive body is charged with the +30 KV DC, there is no measurable thrust upward.

Experiment #2 :

The ESP has been placed in a vertical position so has to have the ogival shape at the top.


When the ESP v1.0, placed vertically ( asymmetrical electrostatic pressure setup as shown in the photo above ), is charged with the +30 KV DC, there is a net thrust upward. The thrust upward is independant of the polarities and remains as long as the ESP is electrostatically charged. The leakage current is very weak ( 3 uA ) at +/-30 KV DC and the measured upward thrust about 0.2 g.

Comments : This experiment confirms that an asymmetrically shaped body is able to generate a thrust along its main axis when it is charged and when the electrostatic pressure is asymmetrical.

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Some documents references :

  • FR Patent N2651388 "Isolated systems self-propelled by electrostatic forces" by Lafforgue Jean-Claude - March 1, 1991
  • Some translations of the Lafforgue's patent can be found here.
  • Dielectric constant reference guide
  • See also :

    The Lafforgue's Electrostatic Pressure experiment

    The LFPT explained : Theory and Principle

    Email : JNaudin509@aol.com

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