POLYSLIDE IST

Intrinsic Sensing Technology monitors cylinder position

Polygon Company in Walkerton Indiana announces a dynamic new addition to its motion controls offering: the newly developed POLYSLIDE IST (Intrinsic Sensing Technology) Smart Cylinder. This product offers embedded resistive sensing technology within a composite laminate tube providing various data feed back.

It seems like a bold statement but new embedded composite cylinder technology has yielded fluid power products far more intelligent than the average 5th grader. How is it possible to create a pneumatic or hydraulic cylinder that can economically and efficiently provide data beyond that of a 5th grader? Let's take a look at this evolving material science. Back in the late 1980's Polygon engineers teamed up with scientists from Xerox to develop embedded conductive fiber architectures that were contained within the insulating structure of epoxy fiberglass laminates. These embedded resistive fibers, which were controlled within a specific resistivity range, were able to provide conductive paths replacing traditional external wire harness packages. In essence a fiberglass structural member could be produced that would provide specific electrical paths, while completely embedded within the mechanical working member. It was from this primary research that a platform was created for the genesis of "smart cylinders". Actually prior to the work with Xerox and without any real application knowledge, Polygon had actually been working with engineers who were developing conductive fuel lines for stealth aircraft at an aircraft frame "skunk works". Composites were required needing both insulating and static dissipative properties. This research work provided application knowledge within the laminate chemistry industry. Leading to the development of a product that is both conductive and electrically insulating.

We fast forward to 2006 and find Sentrinsic LLC, an incubated technology entity from Georgia Tech University, needing to find a practical material platform to house their newly developed Intrinsic Sensing Technology. Sentrinsic had developed a technology that incorporated a non-contacting coupling between a cylinder's piston and an Intrinsic Sensing tube. Through the non-contacting coupling, the voltage amplitude is sensed on the pickup. This voltage amplitude reflects the position of the moving piston without the need for a physical wiper. The repeatability and physical simplicity of this design is totally unique providing data feed back such as linear positioning, vibration, cycles and other relevant information. The main issue Sentrinsic faced was how to create a structure that was both insulating and conductive, but only within a limited resistivity range. Their earliest attempts were to use glass as an insulator combined with traditional metallic tubing. The fragility of the glass and trying to control resistivity levels made this approach very impractical, as well as economically unviable. Through industry contacts Polygon was uncovered with their years of creating conductive composites.

Traditionally the approach to making even a simple sensing cylinder has been to gun bore the piston rod, mechanically affix the positioning apparatus and attach the electronics. This traditional approach is significantly more expensive, as well as limited in stroke and certain hostile operating environmental conditions. The accuracy and linearity of a value using the conductive composite approach is only dependent upon the micro-processing capabilities in place, not the manufacturing techniques incorporated for the metallic materials. Essentially a sensing cylinder could be made in an unlimited length with a mechanical resolution that is infinite.

Polygon and Sentrinsic are now working together to further develop "smart cylinders" or more properly defined as "health monitoring" cylinders for several beta-site applications. Their developmental relationship allows a designer to create a system that balances resolution, linearity, outputs and manufacturing costs based upon the specific needs that the application requires. The next stage is actually embedding RFID chips into the composite laminate to provide all types of data feed back, which is almost unlimited in variation and type. Polygon has also successfully embedded flexible circuitry paths that provide sensing for all types of products that move far beyond pneumatic or hydraulic cylinders.

Our cylinders are smarter than the average 5th grader. In fact these cylinders have enlisted for graduate work during robotic manipulation for the US Military in sensitive bomb detection situations. Additionally Polygon's composite research has demonstrated the capability of sleeving traditional high-pressure hydraulic tubing with a hybridized composite metallic structure using the embedded Sentrinsic sensing technology. One day, in the not too distant future, we will actually be able walk out to our pneumatic or hydraulically actuated machinery and ask, "How are things going today" and hear in return "cycling well but I have this constant vibration in my right pivot joint."