DARPA’s Defense Sciences Office (DSO) is aggressively pursuing the development of novel materials with the potential to boost national security. Shown here are images depicting (left to right) a cold-plasma materials deposition process, an ultra-low-density structural material, and precision molecular modeling for designing new materials.
during a variety of process treatments such as heating, cooling, pressing, or extruding. Processing these new, complex materials in a way that meets performance specifications at high yield with predicable properties proved to be a significant challenge. To attack this problem, DARPA convened an extensive set of discussions and brainstorming sessions involving DARPA program managers, professionals in the manufacturing trenches, and advisers on the Defense Sciences Research Council (DSRC) to determine how to advance the field of materials processing for these emerging complex materials. The result was the Intelligent Processing of Materials (IPM) program, that in the words of Dr. Haydn Wadley, Edgar Starke Professor of Materials Science and Engineering at the University of Virginia, “was sufficiently general that it could – and eventually was – applied to almost every materials process, yet sufficiently precise that it could reduce the variability of each of these processes.” The concept of IPM is to use in-situ sensors to monitor a material manufacturing process as it unfolds, and to compare what you are measuring at each step with what the process models are predicting the state of the material to be. If there is a variation between what is measured and what is predicted, then engineers can use the process models to determine what processing parameters they need to adjust to get the process under control. IPM was a perfect fit for DARPA, as it was enabled by a confluence of game-changing capabilities in microelectronics, computer science, and a new concept, artificial intelligence – all technologies championed by DARPA.
DEFENSE ADVANCED RESEARCH PROJECTS AGENCY I 60 YEARS
The vision of IPM could not have been more alluring to materials scientists, who at that time still generally relied on measurements made after the process was done to determine if a material they were trying to deliver was likely to meet specifications for a given application. “The idea was not just to measure the heating cycle, pressure course, chemical environment, and other relevant variables in a materials manufacturing process, but to also sense the attributes of the material that dictated its performance for its intended application,” Wadley explained. “[IPM] has had a transformational impact upon the processing of materials. It rapidly spread and is pervasively used everywhere materials are processed – from integrated steel mills to microelectronic foundries,” he added. What’s more, Wadley noted that the practice of IPM yields a “digital twin” of a manufactured material, that is, a digital record of the specific evolving environment that brought a batch of material into existence. This is just the sort of data that researchers subsequently could summon to address weaknesses in their materials models and in the expert systems and other artificial intelligence (AI) tools that the IPM adventure revealed. IPM changed how materials were made. As IPM took hold in the materials and manufacturing communities in the 1990s, it presaged how the coming Information Age would continue to drive the evolution of how materials are invented, made, and deployed. Emblematic of this phase was the emergence of solid free form (SFF) manufacturing, now known more familiarly as 3-D printing or additive manufacturing. This opened the way to forming material structures layer-by-layer and even point-by-point straight from a digital file. “The focus was on ceramic components, which were notoriously hard to prototype because they required expensive molds or machining, typically with diamond abrasives,” explained Dr. William Coblenz, a ceramic scientist and former program manager. “Only designers who absolutely needed the properties the ceramic provided, or those with negative risk aversity, would design with ceramics.” As a result, many of ceramics’ fantastic properties, among