The Damysos Gravity Control system is a device that enables a heavier than air object to overcome gravity and achieve controllable weightlessness in earth atmosphere. In 2131 these devices were uncommon and restricted to experimental machines such as a few ES.W.A.T. Landmate units, and some prototype cars. By 2133, the timeframe of Ex Machina, it had come to replace most winged aircrafts and had been fitted to nearly every Landmate in the ES.W.A.T. fleet.
Disappointingly, the Damysos system is one of the few technologically dubious aspects of the Appleseed franchise when it makes its first appearance in a levitating car. For example, despite the grandeur of the Landmates and the staggering presence of the Bioroid species of humans, these things are at least explained to some level of satisfaction, using plausible concepts, historical background, and a minimal amount of technobabble, unlike other futurist sci-fi franchises. The Damysos, on the other hand, merely exists and is barely explained at all. When it is, the vague explanation nearly falls prey to the Star-Trek level of pseudoscience, nearly, but not quite. After Deunan declares that Hitomi's car "feels strange," during a ride to the Olympus Legislature, Hitomi plaintively explains that "high-frequency oscillation" is neutralizing the weight of the vehicle and making it float several inches off the highway. The terminology, not really that valuable to a layperson, could however suggest that the Damysos is some sort of variation or improvement on a gyroscopic gravity control device, though this theory was largely disproven as far back as the nineteen seventies.
Unfortunately, even if the movie is set a hundred and twenty years in the future, most of the scientific community today believes anti-gravity, through a mechanical device, is principally unachievable, regardless of technological advancements or innovations. It's believed, however, that gravity control could still be possible in the largely unexplored field of dark energy science, or the principles demonstrated in the Casimir Effect.