The Biefeld-Brown is a fascinating effect with which levitation can be reached without moving or rotating elements. Static voltage is applied between asymmetric electrodes and a force towards the small electrode is generated. This effect is studied experimentally in this paper. Using this effect a set of experiments is conducted trying to clarify the relation of the model geometry to the induced force. The results show clear relations of the generated force to the model structure and dimensions. As the asymmetry is stronger, the force is stronger. According to the experimental results, a set of preferred parameters is given to strength the effect. Choosing the geometrical properties properly led to improvement of factor ∼9 in the generated force and efficiency. Nevertheless, some results provides contradictions to earlier models of electrohydrodynamicmic (EHD) describing the effect and reveal unresolved questions regarding this effect.

Although the Biefeld-Brown effect was discovered over 80 years ago,1 only limited number of publications were published in the scientific literature describing it. This effect occurs when a device with two asymmetric electrodes is connected to a few kV voltage. A force is obtained pushing the device towards the small electrode, regardless of the voltage polarity. Levitation can easily be obtained without any moving parts. The scientific attention drowned to explain this fascinating effect was very little for many years. But unlike other effects, building a setup demonstrating this effect can be done by rather simple means. Therefore, at the recent years many amateurs built a ‘home-made’ setup and uploaded a ‘youtube’ movie demonstrating the effect with the nickname ‘Lifter’. Most of the physicists and engineers seeing these movies are first fascinated by it, and then categories it as some kind of either photomontage or magician trick. But with some patient, after watching many of these movies, one's healthy curiosity must rise. They can't all be fraud. So we have decided to check it out in laboratory conditions and perform a controlled experiment. First, a levitating model was built imitating models seen in the movies. After few failure models, indeed the fascinating effect of levitation without any moving parts was obtained in the lab.2 Two asymmetric electrodes fixed on balsa wood sticks, connected to a voltage power supply were levitating in a stable manner as described in details below.

Scientific literature exploration showed that the theory describing this effect is still immature. Early ideas suggested different explanations of unknown physics, but recent works rejected these ideas and described the force as an outcome result of ion wind,3–8 an electrohydrodynamicmic (EHD) effect. Few experiments were carried out to support these theories and fair agreement between the theoretical prediction and the experiments was reported for the described setup. NASA has shown an interest in this effect in several reports, and in Ref. 9 from 2004 it is stated that “there is surprisingly little experimental or theoretical data explaining this effect.” Another recent comprehensive work was done in NASA10 at 2009, in order to examine whether this effect could be scaled to values of interest for aircraft propulsion.

In this experimental study, parametric measurements were done trying to relate the generated driving force of the Biefeld-Brown effect to the structure of the model. Such experimental results may help understanding the nature of the force, and even reveal ways to maximize the effect. Indeed, such relations between the model structure and the generated driving force were experimentally found as described further on. Also, some contradictions to the earlier suggested EHD models are found experimentally.

In order to demonstrate the levitation effect a model was built from balsa wood, aluminum foil and copper wire as seen in Fig. 1. The parameters of the model are in Table I.

FIG. 1.

The ‘lifter’ arrangement. A General schematic (a), and a picture of the experimental device (b).

FIG. 1.

The ‘lifter’ arrangement. A General schematic (a), and a picture of the experimental device (b).

Close modal
Table I.

The parameters of the lifter.

Lifter parameterValue
Aluminum foil width 2 cm. 
Triangle side length 21 cm. 
Distance between the Copper wire and the aluminum foil 3 cm. 
Copper wire diameter 0.133 mm 
Aluminum foil thickness 0.03 mm. 
total model weight 1.72 g 
Lifter parameterValue
Aluminum foil width 2 cm. 
Triangle side length 21 cm. 
Distance between the Copper wire and the aluminum foil 3 cm. 
Copper wire diameter 0.133 mm 
Aluminum foil thickness 0.03 mm. 
total model weight 1.72 g 

A high voltage power supply with changeable polarity and digital readings of the voltage and current (Spellman SL1200) was connected to the model as seen in Fig. 1(a). The connection of the power supply was done in four different ways (Table II):

  1. The copper wire was connected to a positive high voltage and the aluminum foil was connected to the ground.

  2. The copper wire was connected to a negative high voltage and the aluminum foil was connected to the ground.

  3. The copper wire connected to the ground and the aluminum foil was connected to a positive high voltage.

  4. The copper wire connected to the ground and the aluminum foil was connected to a negative high voltage.

Table II.

Circuit configurations.

 
graphic
graphic
graphic
graphic
 V(kV)P(W)V(kV)P(W)V(kV)P(W)V(kV)P(W)
Takeoff 16.65 2.83 –17.64 3.18 20.19 6.66 –17.89 5.01 
Minimum needed for levitation 16.19 2.42 –17.41 2.96 18.72 4.31 –17.37 4.17 
 
graphic
graphic
graphic
graphic
 V(kV)P(W)V(kV)P(W)V(kV)P(W)V(kV)P(W)
Takeoff 16.65 2.83 –17.64 3.18 20.19 6.66 –17.89 5.01 
Minimum needed for levitation 16.19 2.42 –17.41 2.96 18.72 4.31 –17.37 4.17 

The results were interesting. One could think that if a certain polarity will lift the model, the opposite polarity will push it down. The results showed different. Both polarities caused force upwards. This result reinforce results in a report made in NASA,9 although it is mentioned in this reference that in certain conditions the forced direction was reversed. We did not see reversal of the force as will be detailed in the following experiments. Also, for the same polarity the location of the ground was important. When the ground was connected to the foil (for both polarities) the levitation was obtained in much lower power and voltage.

In every configuration the minimal voltage and power needed for ‘takeoff’ of the lifter, and the minimal voltage and power to keep the levitation were measured. The experimental results are given in Table II. The minimal flight and levitation voltage and power were obtained when the copper wire was connected to a positive voltage and the aluminum foil was grounded (connection # 1).

Already at the end of this experiment a clear observation is made: this device creates a wind downwards (in all four connections). It is easily felt and seen. To demonstrate it small objects were placed in the device vicinity and the generated wind blow them away. Also a smell is noticed that can be related to ionization. Experienced experimentalist indicated that it is the smell of Ozone, but it was not further checked.

Although the levitation configuration is fascinating, it is not convenient for the exploration of the effect. Aside from the minimal voltage for takeoff and minimal voltage for maintaining levitation, recording continuous data as a function of the voltage increment is difficult. Therefore, a model with reversed configuration was built. In this model the small electrode was placed in the bottom and the large electrode was placed above. As a result, the force in this model operates downwards. We named it ‘Pressing model’. The model was placed on a digital scale and measurements of the weight were continually taken for varying voltage. Several experiments were done with the ‘Pressing model,’ trying to identify the relation between the device structure and the obtained weight. First, the influence of the electrodes gap was checked for various dimensions of the small electrode, and then systematic modification of the structure was done by adding elements. Following is the experiments description followed by the results. General dimensions of the models are in Table III.

Table III.

General dimensions of the models.

 Copper wireDistance between the copperFoil widthFoil height
Modelthickness [mm]wire and the foil [cm][cm][cm]
Levitating 0.133 21 
Pressing 1 0.133 Changing 26 
Pressing 2 0.133 2.5 26 Changing 
Ruggedized pressing Changing 2.5 26 3.5 
 Copper wireDistance between the copperFoil widthFoil height
Modelthickness [mm]wire and the foil [cm][cm][cm]
Levitating 0.133 21 
Pressing 1 0.133 Changing 26 
Pressing 2 0.133 2.5 26 Changing 
Ruggedized pressing Changing 2.5 26 3.5 

Experiment #1 – Electrodes gap influence (Fig. 2)

FIG. 2.

Arrangement of pressing model 1 with changeable distance between the copper wire and the foil.

FIG. 2.

Arrangement of pressing model 1 with changeable distance between the copper wire and the foil.

Close modal

The first experiment is intended to check the influence of the electrodes gap on the generated force. The ‘Pressing model #1’ was built from Balsa wood and set on a scale with an accuracy of 0.01g. A ruler was placed on the side of the model for determining the distance between the copper wire and the aluminum foil. A copper wire was stretched between two holders located on both sides of the model, enabling a distance changing between the copper wire and the foil. The copper wire was connected to a positive high voltage and the aluminum foil was connected to the ground, the voltage was changed gradually and readings of the current and weight were taken.

The experimental results are seen in Figs. 3 and 4. As clearly seen, for shorter gap a greater weight is measured in the same voltage and power. However, the maximal possible weight without breakdown was not obtained for the shorter gap as well.

FIG. 3.

Weight dependence on the voltage for various gaps between the copper wire (0.133 mm) and the aluminum foil.

FIG. 3.

Weight dependence on the voltage for various gaps between the copper wire (0.133 mm) and the aluminum foil.

Close modal
FIG. 4.

Weight dependence on the voltage for various gaps between the copper wire (0.133 mm) and the aluminum foil.

FIG. 4.

Weight dependence on the voltage for various gaps between the copper wire (0.133 mm) and the aluminum foil.

Close modal

Experiment #2adding small electrodes (Fig. 5).

FIG. 5.

Arrangement of multiple wires pressing model experiment. General schematic (a), and a picture of the measured device (b).

FIG. 5.

Arrangement of multiple wires pressing model experiment. General schematic (a), and a picture of the measured device (b).

Close modal

This experiment and the following one are intended to check the influence of each electrode on the generated force. Four copper wires with a 0.133 mm diameter were added gradually and stretched at a distance of 2.5 cm from the aluminum foil. The copper wires were connected to a positive high voltage and the aluminum foil was connected to the ground. The voltage was changed gradually and readings of the current and weight were taken.

The experimental results are given in Fig. 6. Adding copper wires significantly reduced the measured weight. In addition, compering the weight for a certain voltage of 25.3 kV (Fig. 7), it is seen that the weight dependency in the number of copper wires is approximately linearly decreasing.

FIG. 6.

Weight dependence of number of wires.

FIG. 6.

Weight dependence of number of wires.

Close modal
FIG. 7.

Weight dependence on number of wires at 25.3 kV.

FIG. 7.

Weight dependence on number of wires at 25.3 kV.

Close modal

Experiment #3 – Adding big electrodes (Fig. 8)

FIG. 8.

Arrangement of multiple foils pressing model experiment. a) General schematic, and b) Picture of the measured device.

FIG. 8.

Arrangement of multiple foils pressing model experiment. a) General schematic, and b) Picture of the measured device.

Close modal

This experiment is complementary to the previous one. It is intended to check the influence of the big electrode on the generated force. The setup of this experiment is seen in Fig. 8. Four big electrodes were built close to each other. Copper wire with a 0.133 mm thickness was stretched at a distance of 2.5 cm from the big electrodes. The copper wire was connected to a positive high voltage supply and the aluminum foils were connected to the ground. The voltage was changed gradually and readings were taken.

The experimental results of this experiment are seen in Fig. 9, adding foils significantly increased the measured weight. As will be seen later on, the weight dependency on the number of foils is approximately linear.

FIG. 9.

Weight dependence of number of foils in Inversed lifter.

FIG. 9.

Weight dependence of number of foils in Inversed lifter.

Close modal

Experiment #4 – Changing distance between big electrodes (Fig. 10)

FIG. 10.

Arrangement of pressing model 2 with changing the distance between two foils.

FIG. 10.

Arrangement of pressing model 2 with changing the distance between two foils.

Close modal

In view of the last experiment, an hypothesis was made that the significant factor related to the generated force increment is the fact that the 4 big electrodes induce a larger volume with approximately uniform potential. So, another setup was made to imitate this situation but with only two electrodes, where the distance between them is changed.

The setup of this experiment is seen in Fig. 10. The model includes two foils of Balsa wood covered with a thin aluminum foil. Copper wire with a 0.133 mm thickness was stretched at a distance of 2.5 cm from the aluminum foils. The copper wire was connected to the varying high positive voltage and the aluminum foils were connected to the ground. The distance between the two foils was changed in steps. The setup was set on a scale and the voltage was increased gradually while reading from the scale were taken.

The experimental results of this experiment are seen in Fig. 11. Changing the distance between the foils did not cause a significant change of the results. This result is quite surprising. The force is not depended on the potential map but it seems to be depended on the number (or area) of big electrodes. So, the following experiments were aimed to clarify or reject this understanding, as described below.

FIG. 11.

Weight dependence of the distance between two foils.

FIG. 11.

Weight dependence of the distance between two foils.

Close modal

Experiment #5 – changing the big electrodes height (Fig. 12)

FIG. 12.

Arrangement of the pressing model 2 experiment with foils height change. a) 3.5 cm high, b) 7 cm high, and c) 10.5 cm high.

FIG. 12.

Arrangement of the pressing model 2 experiment with foils height change. a) 3.5 cm high, b) 7 cm high, and c) 10.5 cm high.

Close modal

The setup in this experiment is seen in Fig. 12. In this setup, the big electrode height was changed (3.5 cm, 7 cm, and 10.5 cm). The rest of the parameters were kept as before. This setup was chosen because although the area of the big electrode is significantly changed in this setup, the change in the potential map between the electrodes is rather small. So if the results depends on the variations of the potential map a minor difference in the results is expected.

The results of this experiment are seen in Fig. 13. It is clearly seen that enlarging the height of the foil increased the weight applied on the scale. Again, a dependence on the large electrode area is obtained even when the potential map is almost the same. This result encouraged us to design another experiment to support or reject this conclusion, as described in the next experiment.

FIG. 13.

Weight dependence of the height of foils.

FIG. 13.

Weight dependence of the height of foils.

Close modal

Experiment #6 – big electrode with and without slots (Fig. 14)

FIG. 14.

Arrangement of the pressing model 2 experiment with foil a 10.5 cm height. a) Without slots, and b) With slots.

FIG. 14.

Arrangement of the pressing model 2 experiment with foil a 10.5 cm height. a) Without slots, and b) With slots.

Close modal

The setup of this experiment is seen in Fig. 14. The model was built on the basis of the former experiment, but slots were made to the big electrode foil (10.5 cm hight). In this way a reduction of the electrode area is obtained but the potential map and the outer dimensions remains with minor variations. The rest of the experimental parameters were remained. The experimental results are seen in Fig. 15. A significantly reduction in the weight was recorded in the slotted model measurement. In this experiment the former conclusion is reinforced: the weight is depended on the area of the big electrode, and a major change is possible even when the potential map between the electrodes remains unchanged.

FIG. 15.

Weight dependence of the foil with or without slots.

FIG. 15.

Weight dependence of the foil with or without slots.

Close modal

Experiment #7 –Horizontal big electrode with changing width (Fig. 16).

FIG. 16.

Arrangement of the pressing model 2 experiment with changing the width of a horizontal foil. (a) Width of 3.5 cm, and (b) Width of 7 cm.

FIG. 16.

Arrangement of the pressing model 2 experiment with changing the width of a horizontal foil. (a) Width of 3.5 cm, and (b) Width of 7 cm.

Close modal

The setup in this experiment is seen in Fig. 16. A model was built with horizontal big electrode with a different width (3.5 cm and 7 cm). the copper wire was starched at a distance of 2.5 cm below the big electrode. The experiments were done is a similar manner to the former experiments. The objective here is to see if the big electrode must be vertical or not. Such a claim is related to the wind effect, since a vertical electrode does not block the wind and horizontal electrode blocks the wind.

The results of this experiment are seen in Fig. 17. It is seen that horizontal electrode also works well, and again increasing the width of the horizontal foil increases the measured weight applied on the scale. However, in this model the potential map also have a certain change.

FIG. 17.

Weight dependence of the horizontal foil width.

FIG. 17.

Weight dependence of the horizontal foil width.

Close modal

It should be noted that a levitating model with horizontal big electrode was also built and it did levitate as well.

Experiment #8– ruggedized device (Fig. 18)

FIG. 18.

Ruggedized multiple foils pressing model experiment.

FIG. 18.

Ruggedized multiple foils pressing model experiment.

Close modal

During the experiments, we have noticed small vibrations of the foil and the wire together with some fluctuations on the readings. This effect led us to conducting the experiment again for the second time with ruggedized model that is less sensitive to these fluctuations. The setup in this experiment is seen in Fig. 18. This model was built from Perspex and four aluminum pieces replaced the foils. Copper wire with a 0.133 mm thickness was stretched at a distance of 2.5 cm from the aluminum pieces. It was stretched stronger since the Perspex did not collapse like the Balsa did. The copper wire was connected to the high voltage and the aluminum pieces were grounded.

The experimental results of this experiment are seen in Fig. 19. Indeed more stable results were measured and therefore the fluctuations can be related to the delicate nature of the former models. The results of ‘adding big electrodes experiment’ clearly repeated in this model as well. However, another impressive result is the comparison between the two experiments (balsa model versus ruggedized model). The measured weight in much higher for the ruggedized model in the same conditions of voltage and dimensions. Clearly ruggedizing the device increased the weight. Comparison of the models is further presented in the discussion paragraph.

FIG. 19.

Weight dependence of number of foils in ruggedized Inversed Lifter.

FIG. 19.

Weight dependence of number of foils in ruggedized Inversed Lifter.

Close modal

Experiment #9 – changing copper wire thickness (Fig. 20)

FIG. 20.

Arrangement of ruggedized pressing model experiment with changing thickness of the copper wire. (a) general schematic, and (b) a picture of the measured device.

FIG. 20.

Arrangement of ruggedized pressing model experiment with changing thickness of the copper wire. (a) general schematic, and (b) a picture of the measured device.

Close modal

The setup in this experiment is seen in Fig. 20. Using the ruggedized model described above, the influence of the Copper wire thickness was measured. Experiments with different Copper wires were made having a thickness of 0.133 mm, 0.17mm, or 1mm. The copper wire was connected to the positive high voltage and reading were taken. The experimental results of this experiment are seen in Fig. 21 and 22.

FIG. 21.

Weight dependence of the copper wire thickness.

FIG. 21.

Weight dependence of the copper wire thickness.

Close modal
FIG. 22.

Weight dependence of the copper wire thickness.

FIG. 22.

Weight dependence of the copper wire thickness.

Close modal

The results in this experiments is opposite to the result with the big electrode. As the small electrode become smaller the weight increase. Since the position of the different wires is the same, again there is no change in the potential map in the gap. However, the field in close proximity to the small electrode is higher, as will be discussed in the discussion.

Experiment #10 – ruggedized device with polarization reversal (Fig. 23)

FIG. 23.

Arrangement of ruggedized pressing model experiment with polarization reversal. (a) general schematic, and (b) a picture of the measured device.

FIG. 23.

Arrangement of ruggedized pressing model experiment with polarization reversal. (a) general schematic, and (b) a picture of the measured device.

Close modal

The setup in this experiment is seen in Fig. 23. The effect of the polarization was checked on the ruggedized model. The experiment was conducted in four forms (in a similar manner to the levitating model):

  1. The copper wire was connected to a positive high voltage, and the Aluminum pieces were connected to the ground.

  2. The copper wire was connected to a negative high voltage, and the Aluminum pieces were connected to the ground.

  3. The copper wire was connected to the ground, and the Aluminum pieces were connected to a positive high voltage.

  4. The copper wire was connected to the ground, and the Aluminum pieces were connected to a negative high voltage.

The experimental results are seen in Fig. 24 and 25. As seen, the strongest effect is obtained for configuration (1), in compatibility to the levitating model experiment.

FIG. 24.

Weight dependence of the polarization.

FIG. 24.

Weight dependence of the polarization.

Close modal
FIG. 25.

Weight dependence of the polarization.

FIG. 25.

Weight dependence of the polarization.

Close modal

The described experiments leads to some clear understandings:

  • This device generates wind that regardless of the voltage polarity always goes towards the big electrode.

  • The most efficient polarity is where the big electrode is grounded and the small electrode is in positive voltage.

  • For bigger big electrode and smaller small electrode, higher force is obtained.

  • An interesting understanding that is stemming from several experiments is that for similar potential map and changed electrode area the force is changed.

  • Vibrations of the electrodes seems to reduce the effect.

In Fig. 26 two of the mentioned effects are seen in a comparative graph. The effect of adding electrodes for a certain voltage (18.5 kV) is seen for the two pressing models. In both of them, a clear dependence on the number of big electrodes is seen. Also a similar tendency is seen. But, for the ruggedized device much higher weight is measured.

FIG. 26.

Weight dependence of number of foils 18.53 kV.

FIG. 26.

Weight dependence of number of foils 18.53 kV.

Close modal

One measured phenomenon related to experiments 3 and 4, should be further discussed. In experiment #3 big electrodes were added, and in experiment #4 the distance between two big electrodes was extended. In both of the experiments the map of potentials is similar in the gap between the small and big electrodes without the ions. What is the reason to the difference in the results of these experiments? why is the generated force behaved differently? We clearly see that if there is a larger area to collect the ions the force in increased. This result is repeated in few experiments, particularly in experiment # 6.

Looking at the various theoretical works3,7,10 for the induced force estimation, similar expressions are proposed with minor differences. In these works it is claimed that that basically the lifter force upwards depends on a volume integral of the current component directed downwards. According to this claim equations are driven to evaluate the thrust force. Eq. 3 at Ref. 3 is formulated as follows:

\begin{equation}F = P \cdot (l/U) \cdot \left[ {1/b \cdot (1 + \varphi)} \right]\end{equation}
F=P·(l/U)·1/b·(1+φ)
(1)

where F is the thrust P is the power, l the electrode separation distance, U the applied potential difference, b the ion mobility (bair = 2.15 × 10–4 m2/V-sec), and φ the fluid performance parameter (φair = 2 × 10−2).

Similar but simpler expression is used in Ref. 10 Eq. 14 (also appears in Ref. 7):

\begin{equation}F = Id/{\rm \mu }\end{equation}
F=Id/μ
(2)

where F is the thrust, I the current, d the gap between the electrodes, and μ is the ion mobility (m2/V-sec).

As seen, the force expressions in these references do not include the size of the big electrode at all. Calculating the force using Eq. (2) according to our experimental parameters gives the results detailed in Table IV. Three different experiments having the same current I, the same gap between the electrodes d, and the same mobility μ are presented in the table. Because of that, the calculated result is the same for all the three experiments. The first experiment describes ‘regular’ lifter construction, and indeed the calculated result resembles the measured result. Nevertheless, in the second line (Exp. 9), where the same current and gap are used with similar voltage and power, but the big electrode is comprised of 4 ruggedized electrodes, the force is ∼9 times stronger. The electric conversion efficiency θ, which is the ratio of the obtained trust to the consumed power is also ∼9 times more, reaching ∼73 N/kW. At the same conditions, the geometrical efficiency ϕ, which is the ratio of the force to the used area is ∼9 times more, reaching 4.8 N/m2. According to the NASA report at Ref. 10, these numbers reach practical values for aircraft. Moreover, there are different working points for higher voltage, where higher geometrical efficiency is reached (7.7 N/m2), but on the expense of reducing the electric efficiency (20.7 N/kW). For lower voltage, the opposite tendency is measured and the electrical efficiency is extended up to 202 N/kW, while the geometrical efficiency is reduced to 4.1 N/m2. All these results are much higher than the predicted by Eq. (2).

Table IV.

measured and calculated force comparison.

        F (mN)  
deviceTypeNDia (mm)Gap (cm)I (mA)V (kV)P (W)MesCalcθ (N/kW)ϕ (N/m2)
Exp.1 Fig. 2  foil (0.03 mm) 0.133 2.5 0.03 14.05 0.422 3.43 3.49 8.15 0.53 
Exp.9 Fig. 20  plate (0.5 mm) 0.133 2.5 0.03 14.34 0.43 31.29 3.49 72.74 4.81 
Exp.9 Fig. 20  plate (0.5 mm) 2.5 0.03 16.4 0.492 7.75 3.49 15.75 1.19 
        F (mN)  
deviceTypeNDia (mm)Gap (cm)I (mA)V (kV)P (W)MesCalcθ (N/kW)ϕ (N/m2)
Exp.1 Fig. 2  foil (0.03 mm) 0.133 2.5 0.03 14.05 0.422 3.43 3.49 8.15 0.53 
Exp.9 Fig. 20  plate (0.5 mm) 0.133 2.5 0.03 14.34 0.43 31.29 3.49 72.74 4.81 
Exp.9 Fig. 20  plate (0.5 mm) 2.5 0.03 16.4 0.492 7.75 3.49 15.75 1.19 

Table IV notations:

Type: the type of the big electrode

N: number of big electrodes

Dia: diameter of small electrode

Gap: the gap between the electrodes

θ: Electric efficiency, the ratio of the force to the power, F/P

ϕ: Geometric efficiency, the ratio of the force to the area, F/A. The area is taken as the device length (26 cm) multiplied by estimated width that is equal to the gap between the electrodes (2.5 cm).

Relating to the last line in Table IV, which also refers to Experiment #9, it is seen that the radius of the small electrode is also important. Although the same current is involved, reducing the small electrode radius results in reduction of the force and both efficiencies in a factor of ∼4 in comparison to the same device with the smaller diameter of the small electrode. That is again, not predicted in Eq. (2). In view of the results presented here, it seems that these EHD models should be further developed to include more complicated geometrical structure.

Possible explanation of the results relates to a space charge effect close to the big electrode. The ions produce a repealing space charge close the big electrode that interfere with the ions collection. When there is a large area to collect the exhausted ions, they are more easily collected reducing the space charge. Further research is needed to verify this explanation.

We have also seen that reducing the small electrode diameter also increase the effect. That is easier to explain, the following explanation is suggested: when the wire diameter is reduced, the electric field around it is significantly enlarged and the ionization can be increased. In this case the map of potential around the small electrode is changed.

Another contradiction to former theories is related to experiment #7 with the horizontal electrode. Ref. 5 claims that ‘‘… when R is infinitely large, which means the ground electrode becomes a flat plate, the thrust decreases practically to zero. …’’ (R stands here for the big electrode curvature radius). But we saw experimentally the opposite: the effect exists with horizontal electrode as well. The claim in Ref. 5 is that “larger radius R also results in increased resistance for airflow”. But we saw the opposite result. When the big electrode was increased the effect got stronger. So again, relating to the horizontal electrode, the EHD model in Ref. 5 do not apply. The suggested explanation for this observation is related to fact that the ions lose energy to the air molecules during all the way to the big electrode through collisions. After each collision the ion is pulled again and in return pulls back the lifter. So, energy is transferred regardless of the orientation of the big electrode. Clearly, an orientation that less interfere the generated wind is preferable, but horizontal electrode still works.

In this experimental study, parametric measurements of the Biefeld Brown effect were done relating the generated force to the structure of the model. Clear observations are:

  • Levitating device without any moving/rotating parts is easily obtained in an asymmetric electrodes geometry.

  • The force is always towards the small electrode disregarding the voltage polarity.

  • Wind is obtained towards the big electrode.

  • The size of the electrodes influence the force: smaller small electrode and bigger big electrode both yields higher force.

  • Structures with similar potential distributions but with different electrode area induce different forces, related to the electrode area.

The experimental results reveal ways to maximize the effect:

  1. Decreasing the distance between the foil to the copper wire

  2. Narrowing the copper wire diameter,

  3. Increasing the number of foils,

  4. Ruggedizing the device,

  5. Increasing the height of the foil,

  6. Stretching tight the small electrode to avoid vibrations,

  7. Polarity – ground to the big electrode and positive voltage to the small electrode are superior.

These experimental results may be the basis to further development of the theoretical EHD model of this effect.

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T. T.
Brown
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A method of and an apparatus or machine for producing force ormotion
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A ‘youtube’ movie of the first model levitating in our lab http://www.youtube.com/watch?v=6EGA4JUssGM.
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M.
Tajmar
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Biefeld–Brown Effect: Misinterpretation of Corona Wind Phenomena
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L.
Zhao
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Adamiak
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EHD flow in air produced by electric corona discharge in pin–plate configuration
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Lin
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Kazimierz
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Numerical analysis of forces in an electrostatic levitation unit
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EHD gas flow in electrostatic levitation unit
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