BTG Labs- The Surface Analyst
A small materials research company in Cincinnati, Ohio, answered a call from the U.S. Air Force in the early 2000s and today finds itself immersed in a revolutionary transition in manufacturing.
Just as aluminum and titanium replaced wood as the building material for aircraft in the middle part of the last century use of composites is changing the face of aerospace manufacturing today. Brighton Technologies Group (BTG) is working with a team of innovators that is ushering in this new era: an aircraft built entirely of carbon fiber composites.
BTG’s part has been to develop an instrument that analyzes the surfaces of composites and other materials to assure optimal adhesion, a vital element in the use of composites, which are lighter, stronger, more flexible and offer more in design potential than materials they are replacing.
The shift to composites is widespread in industry, according to Lucas Dillingham, sales engineer for BTG. “All of a sudden people can design things in new ways. With the information we provide and how that information relates to how you build something, we’re influencing how people are designing and building things — whether it’s an automobile or an airplane.”
Developing lighter materials has been a chief focus of the U.S. Air Force for decades. An Air Force transport plane often reaches its weight limit before it runs out of space. So reducing the weight of the even the smallest components in tools, gear, equipment and the aircraft itself is a constant goal.
In the early 2000’s the Air Force was looking for ways to use composites in the manufacturing of the F-35 fighter jet. But there were problems with joining and bonding composites that presented obstacles to their use.
Traditional joiners in the aerospace industry — rivets and bolts — are made for thicker, more substantial materials and composites often broke up around the heavy fasteners. It became clear that adhering composites was the way to go to avoid use of rivets and bolts, but knowing how to adhere them to each other or other materials remained problematic.
Enter Giles Dillingham, a materials scientist and chief scientist at BTG. In 2005 his work centered on helping manufacturers such as Caterpillar and The Boeing Company analyze adhesion properties of surfaces. Following an Air Force request, Brighton Technologies secured a Phase I Small Business Innovation Research contract to develop a method for measuring surface readiness for bonding between composites, metals and other materials.
Giles Dillingham assembled a team of three researchers. Their task was to develop a tool that was small, handheld, able to quickly analyze a surface and capable of providing ready numbers to indicate how a bond would work. Unlike other methods in use, it would need to be taken on the manufacturing floor and produce answers within seconds. With the help of a Phase II SBIR grant, BTG developed a prototype that could do all of the above.
Today, after constant innovation and three iterations of the instrument, the Surface Analyst™ is being used widely in industry — from paint companies to medical device makers to car manufacturers And it will be included in all sales of the F-35 by Lockheed Martin as part of the repair equipment package that comes with the jet.
The history of adhesion is an interesting one. Ever since people started trying to adhere one surface to another there has been a question: will it stick? The answer has often been left to trial and error. If it sticks, the next question is, will it stay stuck?
Engineers and researchers understood that the correct “wetting” of the surface was key to adhesion. A consistent surface energy was needed for bonding processes between materials and various methods and technologies were used to analyze surfaces. But none were easily transportable and few were consistently dependable; some destroyed the surface.
BTG researchers knew that a key method of determining correct wetting was how a drop of liquid spread on a surface: if the drop spread out, creating an angle of 30 degrees or less between the surface and the top of the water drop, the surface likely had the correct wetting; it if beaded, creating a larger angle, it did not.
Lucas Dillingham reports that, as is common with all research and development, BTG had to work within constraints, in a sense “solving a problem within a box” to develop the Surface Analyst. One of the breakthroughs in the research was finding a way to measure a water droplet from above to understand the angle it formed with the surface, instead of looking at it from a side angle.
“The big strength for the system is that we’re measuring the droplet from the top,” says Dillingham. “This allows a lot of flexibility. You don’t need mirrors, a periscope. Another big advantage is the way we put the droplet down. We shoot it down with an inkjet valve.” (Previous methods of wetting had used a water syringe.)
Today’s Surface Analyst (4.2 x 2.1 x 9 inches) uses a camera at its base to capture an image of a drop of lab-grade water adhering to the top two to three molecules of a surface. The image is sent to a microprocessor in an Android-based system with a custom graphic user interface. That data is used to create a spreadsheet that provides a number on an LCD touchscreen that registers the state of the surface as well as a number that reflects the necessary condition for quality bonding. That information can be readily downloaded from the instrument through a USB port.
The Surface Analyst can measure a surface in generally about two seconds. It can analyze composites, metals, polymers and biological surfaces. Designed for shop floor use, the instrument head is attached to a tether to ensure flexibility.
“People are using it in three ways,” Dillingham says. “In development, engineers are saying, if my surface is between 20 and 30 it’s going to work. Mode two is once you’ve developed that number and have technicians out there manning the line, you want to make sure the quality you developed in the lab is going to work, so your technician can do the daily checks to see that you get the surface you want. The third is when there’s a failure. Things aren’t sticking anymore. The technician can write an email saying he’s getting 69 when he should be in the 30s — there’s something wrong here.”
Dillingham reports that the Air Force has purchased a few of the instruments and Lockheed Martin estimates it saved an estimated $25 million from implementing 12 Surface Analysts the first nine months of 2015. The U.S. Naval Air Systems Command has done preliminary testing and is planning to use the Surface Analyst on aircraft carriers so the surfaces of aircraft components can be analyzed and repaired at sea.
In the last two years, BTG has found many other industries that have a need for the tool. “If you bond, coat, clean, seal or paint, you care about your surface — that it’s prepared correctly every day,” says Dillingham, who spent the early part of his career in the commercial sector.
Today Dillingham is marketing the Surface Analyst to a wide range of companies, including Johnson & Johnson, Microsoft, Proctor & Gamble, Jeld-Wen, Ford, Tesla Motors and Sherwin Williams. BTG has also found a use for the instrument in the medical field — to assure cleanliness in implanted medical devices. In the automotive industry, the Surface Analyst is used to assure a surface is in prime condition to receive paint. He reports that hundreds of Surface Analysts have been sold in the last two years.
However, the real excitement at Brighton Technologies comes with the knowledge that their tool is helping usher in a new way of manufacturing.
“You don’t have to use wet chemical processes that are harmful to the environment,” Dillingham explains. “You don’t have to put a bolt where you normally would. You can use water-based paint. You understand what is going on at the surface level, so you can now take advantage of these new materials and design concepts.”
The Air Force and aerospace industry remain central to BTG’s focus. “One of the big things were working on right now is the DARPA [Defense Advanced Research Projects Agency] TRUST program to fully certify a totally-bonded aircraft – an aircraft that has no bolts at all – that is totally glued together,” Dillingham says. “The only way that is possible is by implementing the concepts and techniques that we’re talking about. That’s why we’re selling the Surface Analyst to such a diverse group of people — whether it’s Apple or Microsoft or Boeing or Airbus. All these people are looking for better performance, better predictability. They want to be able to design things with new materials and we’re giving them the tools to be able to do that.”