The C-Motive guys have PR all over the web.

Electrolytic capacitors can have far more capacitance than air capacitors. That's the basic concept here.

Here's their patent.[1] Just scroll through the drawings and you'll see how it works.

Here's the key concept: "Numerous aspects of the present disclosure cooperate to increase the breakdown field strength 8406, and / or adjust (e.g. , flatten) the field strength trajectory such as : the permittivity of the dielectric fluid; a selection of fluid constituents to maintain a permittivity profile related to operating temperatures; protection of the dielectric fluid from impurities, presence of water, and / or presence of gases ; providing a surface smoothness of the electrodes 8402, 8404 (or portions thereof), related surfaces, and/ or a housing inner surface ; rinsing / removal of particles and / or impurities (e.g., from manufacturing residue, etc.); provision of a surface treatment on at least a portion of an electrode, and / or on a surface adjacent to the electrode, including varying surface treatments for different electrodes; provision of a coating on at least a portion of an electrode and / or on a surface adjacent to the electrode, including varying the coating for different electrodes; provision of a surface treatment and / or coating on a component at least selectively contacting the dielectric fluid (e.g., a housing inner surface, a packed bed, a side chamber, flow path, and / or eddy region ); protection of composition integrity of the dielectric fluid (e.g., managing materials of bearings, seals , plates , etc. to avoid material breakdown and / or introduction of degradation constituents that negatively affect the performance of the dielectric fluid ); introduction of a field disrupting additive into the dielectric fluid ( e.g., a coated metal oxide, a nano-particle, and /or a conductive particle having a conductor that isolate the conductive particle from physical contact with the dielectric fluid ); introduction of an ion scavenging additive into the dielectric fluid ( e.g., BHT, antioxidants, etc. ); management of gap distance (e.g., using bearings, magnetic separation, a separation assembly, etc.); and / or selected field weakening at certain operating conditions. The utilization of various field management aspects of the present disclosure allows for an increased average field strength in the gap, while maintaining a peak field strength below a breakdown threshold 8406, thereby increasing capacitive energy storage and consequent performance of the ESM 1002."

This thing is sort of like a high voltage electrolytic capacitor with moving parts. They go to a lot of trouble to deal with most of the problems that happen inside capacitors, plus the special problems from moving parts. They had to go all the way to a pumped fluid system with filters, to keep the dielectric fluid cool and clean. Many electric car motors have liquid cooling, so it's no worse than that. It does mean this is probably a technology for larger motors, because the motor requires some accessory systems.

It's not clear that this is a win over magnetic motors, but it's reasonable engineering.

[1] https://patentimages.storage.googleapis.com/cf/eb/f0/6d48f07...

I've long wondered if there's a possible application for something like this using 3d printing and electrets. Basically you can freeze an electric field inside of an insulator if you apply it as the material solidifies. I think you should be able to embed electrets inside of 3d prints simply by generating a strong electric field at the print head or slightly behind it. You can also vary the field and embed a 3d electret that can act as, say, a sensor or a hidden ID in the print.

I wish they had some examples of what RPM, torque, weight, and size specs were for a few possible applications. They seem to emphasize low RPM, but is that 200 RPM or 2000RPM? With other electric motors being capable of 10k-20k RPM, the "low" RPM mention is very vague.

If it's capable of up to about 3000 RPM, and it doesn't weigh too much it could be interesting as an ultralight aircraft power plant.

Some more technical content (literature review, but includes the university work this spun out of) if the sales page isn't doing it for you:

https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=919...