Manufacturing

New materials that perform better than previous ones or with unprecedented properties open pathways to new and improved technologies. F-15 and F-16 fighter aircraft, still in use by the Air Force today, owe much of their performance advancements to materials technologies that emerged from DARPA materials development programs conducted in the 1970s and early 1980s.

The inherent goodness of miniaturizing electronics has been key to a wide array of technology innovations and an important economic driver for several decades. For example, the seemingly endless shrinking of the transistor has allowed the semiconductor industry to place ever more devices on the same amount of silicon. Each time the size shrunk, transistors became faster and used less power, allowing increasingly capable electronics in smaller packages that cost less. In recent years, power requirements, excessive heat and other problems associated with physical limitations have reduced the advantages of continuing to shrink size.

The sophisticated electronics used by warfighters in everything from radios, remote sensors and even phones can now be made at such a low cost that they are pervasive throughout the battlefield. These electronics have become necessary for operations, but it is almost impossible to track and recover every device. At the end of operations, these electronics are often found scattered across the battlefield and might be captured by the enemy and repurposed or studied to compromise DoD’s strategic technological advantage.

Many military radio frequency (RF) systems, like radar and communication systems, use a class of power amplifiers (PAs) called monolithic microwave integrated circuits (MIMIC). MMIC PAs using gallium nitride (GaN) transistors hold great promise for enhanced RF performance, but operational characteristics are strongly affected by thermal resistance. Much of this resistance comes at the thermal junction where the substrate material of the circuit connects to the GaN transistor. If the junction and substrate have poor thermal properties, temperature will rise and performance will decrease.

Used and non-authentic counterfeit electronic components are widespread throughout the defense supply chain; over the past two years alone, more than one million suspect parts have been associated with known supply chain compromises.

Military platforms—such as ships, aircraft and ground vehicles—rely on advanced materials to make them lighter, stronger and more resistant to stress, heat and other harsh environmental conditions. Currently, the process for developing new materials to field in platforms frequently takes more than a decade. This lengthy process often means that developers of new military platforms are forced to rely on decades-old, mature materials because potentially more advanced materials are still being tested and aren’t ready to be implemented into platform designs.

Many common materials exhibit different and potentially useful characteristics when fabricated at extremely small scales—that is, at dimensions near the size of atoms, or a few ten-billionths of a meter. These “atomic scale” or “nanoscale” properties include quantized electrical characteristics, glueless adhesion, rapid temperature changes, and tunable light absorption and scattering that, if available in human-scale products and systems, could offer potentially revolutionary defense and commercial capabilities. Two as-yet insurmountable technical challenges, however, stand in the way: Lack of knowledge of how to retain nanoscale properties in materials at larger scales, and lack of assembly capabilities for items between nanoscale and 100 microns—slightly wider than a human hair.

Advanced software and equipment to aid in the fight against counterfeit microelectronics in U.S. weapons and cybersecurity systems has been transitioned to military partners under DARPA’s Integrity and Reliability of Integrated Circuits (IRIS) program. Researchers with SRI International, an IRIS performer, announced today they have provided Advanced Scanning Optical Microscope (ASOM) technology to the Naval Surface Warfare Center (NSWC) in Crane, Indiana, where it will join an arsenal of laboratory equipment used to ensure the integrity of microelectronics.