Air Force officer’s inventions inspired by Pin Art, E Ink


When Capt. Daniel Stambovsky, a physicist assigned to the 32nd Intelligence Squadron, left his assignment at the Air Force Research Laboratory in Rome, New York, he left several patents pending. To his surprise, he recently received notification that two of his patents have been approved.

A patent for an invention is the grant of a property right to the inventor, according to the U.S. Patent and Trademark Office. Although Stambovsky is listed as the “inventor” of the patent, the Department of the Air Force does own the rights to the patents.

Stambovsky’s military career didn’t begin with inventions. He entered the Air Force as an enlisted Airman and worked on ground radar systems. Then, he applied and was selected for the Reserve Officers' Training Corps. After he received a Bachelor of Science and was commissioned, he spent five years as a physicist and nuclear engineer at the Air Force Research Laboratory.

“I was able to develop, get funding for and work a project designing antennas with configurable geometries,” said Stambovsky of his work at the Laboratory. “I also worked with a machine-learning, reservoir-computing group, and was on a developmental test team for an airborne communication and tracking system utilizing the MUOS [mobile user objective system] satellite constellation.”

Actuated Pin Antenna Reflector

Stambovsky began working on a reflector for the antenna design when he arrived at the AFRL in 2012. He was inspired by his enlisted experience with the Precision Approach Radar’s antenna system.

The Precision Approach Radar’s antenna system used a standard reflector off a radio frequency beam that bounces each location of the reflector correlated with a grid position down the runway, Stambovsky said. “By moving the beam across the reflector, different grid positions could be targeted by the radar beam. I wanted to invert that process by building a reflector composed of a series of mobile segments, in this case, small flat pins which can be physically actuated to change the shape of the reflector itself.”

Stambovsky used a “Pin Art” desktop toy composed of a bed of pins (the type that can create the image of someone’s hand or face). He manually imprinted a series of shapes into the surface using Legos. A radio frequency sweep was bounced off of the shaped surface into a receiver, he said.

“By analyzing the reflected signal and running it through machine-learning software, I could get the computer to recognize the shape importuned on the pin surface based only on the frequency, amplitude data of the reflected RF,” Stambovsky said.

In theory, by knowing what signal he wanted to reflect in a specific direction, Stambovsky merely needed to grab the associated shape and impress it onto the reflecting pins. Once the pins were mechanically actuated, algorithms could be implemented to permute their reflector’s shape on-the-fly, constantly maximizing the signal strength and gaining improved operation in a dynamic environment, Stambovsky said.

Radio Frequency Emissive Display Antenna and System for Controlling

Stambovsky’s second patent was inspired an article on how E Ink screens, like those on electronic book readers, function.

“Essentially, they [electronic book readers] have an array of pixels, which are micro-containers with fluid in which black ink particles are suspended,” Stambovsky said. “The ink particles are naturally charged, while the fluid itself is not. A small bias voltage applied to the bottom of the pixel will either push the ink particles to the top, where they are visible, or draw them to the bottom, which will make the pixel appear white.”

Stambovsky believed using this same principle with a conducting fluid and similar particles could create the same effect.

When conducting fluid is pushed to the top of the antenna surface, the fluid is displaced, making that segment non-conductive, he said. “If the displacing particles were drawn to the bottom of the ‘pixel,’ that segment would become conductive.”

Stambovsky said each pixel would have a small effect, but when combined with a conducting ‘image,’ the effect would be produced on the surface, creating an active portion of the antenna. If new performance parameters are required, the physical geometry of the antenna could be shifted in the same way an electronic screen changes pictures.

“If it (the “display” style antenna) pans out, this could theoretically yield a very adaptable, low-profile system that is more capable than many that are currently in use,” Stambovsky said.

“It’s a long way off, but reconfigurable antennas are an up-and-coming technology,” he said. “I’m proud to have teamed with others at Rome to start an AFRL effort in this direction. I probably won’t get to see the final results of my efforts, but that’s just the nature of research and the AFRL mission.”

Stambovsky has three additional patents pending approval.  With a bit of luck, all five may eventually hang on Rome’s wall of patents.

Once approved, the term of a new patent is generally 20 years from the date on which the application for the patent was filed in the United States or, in special cases, from the date an earlier related application was filed, and subject to the payment of maintenance fees.

The Air Force Research Laboratory is a global technical enterprise, boasting some of the best and brightest leaders in the world, according to its website. The lab’s mission is leading the discovery, development and integration of affordable warfighting technologies for air, space and cyberspace force.