Engineers at the UD Research Institute developed a laser system so successful in its initial intended use in composites processing that the institute opened a new lab to exploit the technology into additional applications in advanced manufacturing.
Representatives from the Air Force and aerospace industry recently joined UDRI in a dedication of the Rapid Applications of Advanced Manufacturing (RAAM) Laboratory, located in the Dayton Composite Center in Kettering, Ohio. The centerpiece technology is RoboCLASP; a robotic, ultrafast laser already proving to be a game-changer in the preparation of composites for bonded assembly, said Michael Pratt, advanced manufacturing engineer and RAAM team lead.
The “CLASP” in RoboCLASP stands for Composite Laser Ablation for Surface Preparation, a significantly advanced alternative to the current and traditional method of hand sanding polymer matrix composite materials to prepare them for bonding. Developed under Air Force funding with support from commercial aerospace partners, the system uses a “femtosecond” laser, which generates ultrashort, high-energy pulses of light to remove resin from composites without damage to the material.
“This is a world-class technology at the University of Dayton Research Institute,” Pratt said. “As far as we can find in our research, we were the first organization in the world to deploy and integrate a femtosecond laser into a portable and handheld system, and we are now the only organization in the U.S. that is actively developing a robotically integrated system for this application.”
The process of hand-sanding composites to prepare them for bonding is not only time and labor intensive, it also requires the operator to wear a hazmat suit because the process generates hazardous waste in the form of plastic media, Pratt said.
“Another challenge is that some composite parts and materials are too delicate to be hand sanded because of the risk of damage to the part if the operator goes too deep. Laser resin removal is not only safer, cleaner, faster and more affordable, the robotic femtosecond laser process — known as athermal ablation — significantly minimizes waste generation and is highly accurate in precisely removing only the resin, with zero risk of damage to the composite material,” Pratt added.
Unlike continuous-wave lasers, which emit a steady beam of light that will ultimately burn a material, ultrashort pulse lasers emit powerful but very short bursts of light — short enough to be measured on the order of femtoseconds, or one quadrillionth (a million/billionths) of a second.
Because each burst of light is so short in duration, there is no time for heat to be generated in the target material before it is broken down and easily removed by vacuum filtration.
UDRI’s first portable femtosecond laser system, developed in 2021 by the Laser Manufacturing Technology Development (LMTD) team led by advanced manufacturing engineer Jared Speltz and later licensed to Albers Aerospace, uses a handheld laser; the newest iteration is robotic.
“By automating the system, we can program it to perform highly complex coating removal tasks,” Pratt said. “The robot scans the material sample to be lased to create a 3-dimensional roadmap, and then automatically adjusts the laser to accommodate the material’s varying geometry, always keeping it in focus so that it ablates specifically what needs to be removed without damage to any other material.”
Adam Hicks, advanced laser manufacturing lead for the digital manufacturing and supply chain branch of the Air Force Research Laboratory Materials & Manufacturing Directorate, said he anticipates the CLASP technology will be transitioned to other applications in manufacturing, with the potential for significant cost savings to the Air Force.
“Composite laser ablation surface preparation is the first of many applications we envision for advanced laser manufacturing within the Air Force,” Hicks said. “CLASP specifically was a reaction to a near-term manufacturing need for the Air Force to reduce the cost and time associated with manual sanding. Working with UDRI, we delivered transitional capability at a speed which I find truly staggering. This is enabled by the willingness and enthusiasm of all of the CLASP partners, but is driven by the innovation and hard work of the technical performers at UDRI.
“While the initial customer for a robotically integrated laser manufacturing demonstration continues to be the CLASP team, we have already identified many other areas where automated ultrashort pulse laser ablation will be transformational. Combined, I estimate that this technology has the promise to save the U.S. Department of Defense tens of millions of dollars in the next few years alone while providing a cleaner, faster, higher quality manufacturing process.”
Pratt said additional applications could include coatings and paint removal, 3D texturing for additive manufacturing, and machining ceramic parts, which are typically difficult to machine. He also said the RAAM and LMTD teams are pursuing funding opportunities to expand the RAAM Lab and its capabilities in those and other areas.
“We’ll also continue to develop the technology in order to expand its applications in advanced manufacturing,” Pratt added. “Our mission at the RAAM lab is to collaborate with all the talented researchers at UDRI to anticipate what our customers’ needs in advanced manufacturing will be in the future, and make sure we’re developing the best solutions now.”
For more information or interviews, contact Pamela Gregg, UDRI senior communications manager, at 937-229-3268 or Pamela.Gregg@udri.udayton.edu.