Historical research guide · 0046 · 2019
System and method for generating forces using asymmetrical electrostatic pressure
Andrew Neil Aurigema · Charles Raymond Buhler, IV · Individual
In one minute
Andrew Aurigema and Charles Buhler’s patent uses electrostatic pressure—the outward stress ε₀E² on a charged conducting surface—and asks whether geometry can make pressure vectors fail to cancel. Its derivation proposes a time-growing momentum and a force based on field strength and surface area, with no mass expelled. The document reports a nine-blade epoxy pendulum article with an average force of about 237 μN at 25 kV. It reports widening a ground plane from eight to fifteen square inches was predicted to multiply force by 1.8 and measured 1.77; it also reports a voltage-squared trend. The specification describes controls intended to separate the effect from Coulomb attraction and ion wind, plus nanoscale and spacecraft applications. It is a patent disclosure; a vacuum repeat remains the needed measurement.
Connection
Chapter 8 asks how you make force without throwing mass away, and this is the most fully documented bench version of that claim: a derivation, a force law you can compute straight from a drawing, a measured number, and a scaling test that landed where the model said it would. The measurement to watch for is the independent repeat — another laboratory’s balance, in vacuum, with a dummy article alongside the live one.
From the source
Electrostatic pressure — the permittivity of free space times the square of the electric field — is a real stress acting outward on a charged conducting surface, and it is distinct from the Coulomb attraction between two oppositely charged surfaces: opposing electrodes pull together by Coulomb coupling while the electrostatic pressure pushes their surfaces apart.Theory of operation of the invention — the ε₀E² relation
Starting from a zero-total-energy centre-of-mass system and setting the differential of the energy–time product to zero, the inventors derive a momentum P(t) = ε₀ t [E₂²A₂ − E₁²A₁] that grows linearly with time, and hence a steady force F = ε₀ [E₂²A₂ − E₁²A₁] on an object whose surface electrostatic pressures do not sum to zero — with no mass expelled.Theory of operation of the invention, equations (1) to (11)
A fabricated nine-blade test article — quarter-inch blades four inches long, potted in high-voltage epoxy, hung as a pendulum against a force meter — produced a net average force of about 237 μN at +25 kV; enlarging the grounded area from 8 to 15 square inches was computed to increase the force by about 1.8 and measured 421 μN, an increase of 1.77.Multi-blade test cases, FIGS. 21 and 22
The force rises with the square of the applied voltage difference, repeatedly, across a variety of shapes, dielectrics, coatings and geometries; the inventors report running the article inside a grounded ITO-coated enclosure and inside a plastic bag, and flipping it 180 degrees to test in both tension and compression, to separate the effect from Coulomb attraction and from ion wind.Multi-blade test cases, FIG. 23A
With a time-varying drive the force acquires an extra term proportional to time multiplied by the field and its rate of change; for a sinusoidal field that term keeps a non-zero average over a full period and carries an extra factor of elapsed time, so the momentum accumulates rather than cancelling cycle by cycle.Embodiments comprising time varying applied voltage, equations (12) to (15)
Because nothing is consumed or expelled, the inventors project a spacecraft whose propulsion mass fraction is around 2 per cent of vehicle mass rather than the roughly 98 per cent taken by a chemical stage with its fuel, oxidiser, tanks, pumps and motors, and whose thruster never has to be switched off; they also set out nanoscale construction using field emission arrays and carbon nanotubes.Scalability; Propellantless propulsion for spacecraft
The way in
https://patents.google.com/patent/US11511891B2/enHow to cite it
Andrew Neil Aurigema, Charles Raymond Buhler, IV, Individual (2019) System and method for generating forces using asymmetrical electrostatic pressure US11511891B2