Microsystems Technology Office Research Articles

The Electronics Resurgence Initiative 2.0 for U.S. Semiconductor Manufacturing

Abstract The second Electronics Resurgence Initiative (ERI 2.0), sponsored by the U.S. Defense Advanced Research Project Agency (DARPA) Microsystems Technology Office (MTO), is focused on driving next generation dual use microelectronics for national security and domestic needs. The initiative focuses on creating U.S. capability for three-dimensional heterogeneous integration (3DHI) manufacturing and pursuing focused research for the manufacture of complex 3D microsystems. This guest editorial describes the outcomes from a three-day summit (Seattle, Washington, August 2023) where the initiative was launched.

Cervical spinal cord injury in a transgenic mouse expressing fluorophores in neurons, microglia, astrocytes, and oligodendrocytes

Spinal cord injury (SCI) most commonly occurs at cervical levels, and such injuries typically impair breathing. Reproducible cervical SCI models which facilitate high resolution evaluation of the tissue response to the injury will aide in the development and testing of therapeutics to improve respiratory function. These models can be evaluated by anatomical assessment of injury lesions. However, tissue processing using traditional immunohistochemistry is limited by the ability of antibodies to penetrate deep within the tissue sample. To address these issues, we studied the PRISM+ mouse, a genetically modified mouse with fluorophores tagging the four major cell types of the central nervous system endogenously express fluorophores, thereby eliminating the need for immunochemistry procedures. In the genetically modified mouse, neurons express YFP (512ex/529em), microglia express GFP (488ex/509em), astrocytes express DsRed (554ex/586em), and oligodendrocytes express CFP (435ex/485em). PRISM+ mice received a mid‐cervical (C3) dorsal‐lateral crush injury and tissues were harvested 3 days later. Initial histological evaluation of the injured spinal cords confirm an absence of neurons in the lesioned dorsal cord, as expected. However, YFP‐positive motor neurons were prominent in the ventral cord. The ipsilesional dorsal quadrant was clearly observed to have increased GFP‐positive microglial infiltration and lack of CFP‐positive oligodendrocytes. At this 3‐day post‐injury time point we detected no astroglial scar, and in fact there were fewer DsRed‐positive astrocytes in immediate vicinity of the lesion as compared to the rest of the spinal cord. Importantly, the fluorophores were robustly detected in all four cell types, and this enabled reliable and automated analysis of the histological sections. These data indicate that the Prism+ mouse provides a useful model for studying the histological response to SCI.Support or Funding InformationThis work was sponsored by T32‐HD043730 (MDS), 1F32NS095620‐01 (KS), SPARC OT2 OD023854 (DDF). 1 R01 NS080180‐01A1 (DDF), the University of Florida Preeminent Initiative, and by the Defense Advanced Research Projects Agency (DARPA) Microsystems Technology Office (MTO), under the auspices of Dr. Jack W. Judy (jack.judy@darpa.mil) and Dr. Doug Weber (Douglas.Weber@darpa.mil) as part of the Reliable Neural Technology Program, through the Space and Naval Warfare Systems Command (SPAWAR) Systems Center (SSC) Pacific grant No. N66001‐11‐1‐4013.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

A Revolution on the Horizon from DARPA: Heterogeneous Integration for Revolutionary Microwave\/Millimeter-Wave Circuits at DARPA: Progress and Future Directions

The Microsystems Technology Office of the U.S. Defense Advanced Research Projects Agency (DARPA) is developing revolutionary materials, devices, and integration techniques to meet the performance requirements for advanced microwave and millimeter-wave (mmW) systems. The DARPA Compound Semiconductor Materials on Silicon (COSMOS) program focused on developing new methods to tightly integrate compound semiconductor (CS) technologies within state-of-the-art silicon (Si) complementary?metal-oxide-semiconductor (CMOS) circuits to achieve unprecedented circuit performance levels. The DARPA Diverse Accessible Heterogeneous Integration (DAHI) program is continuing that work by developing heterogeneous integration processes to intimately combine advanced CS devices, as well as other emerging materials and devices, with high-density Si CMOS technology. DARPA has also pushed limits in Si technology and driven seminal developments in gallium nitride (GaN) device technology. Taken together, these programs are addressing many critical challenges for next-generation microwave and mmW systems and seek to revolutionize U.S. Department of Defense (DoD) capabilities in these areas.

Near-Junction Microfluidic Cooling for Wide Bandgap Devices

ABSTRACTGaN has emerged as the material of choice for advanced power amplifier devices for both industrial and defense applications but near-junction thermal barriers severely limit the inherent capability of high-quality GaN materials. Recent “embedded cooling” efforts, funded by Defense Advanced Research Projects Agency Microsystems Technology Office (DARPA-MTO), have focused on reduction of this near-junction thermal resistance, through the use of diamond substrates and efficient removal of the dissipated power with convective and evaporative microfluidics. An overview of the accomplishments of the DARPA Near-Junction Thermal Transport (NJTT) program and recent results from the on-going DARPA Intra-Chip Embedded Cooling (ICECool) program are provided. It is shown that growth or bonding of diamond to GaN epitaxy has enabled a 3-5× increase in power handling capability per transistor unit area, while use of microfluidic cooling has enabled heat fluxes of 30 kW/cm2at the transistor level and 1 kW/cm2at the die-level, for a 3-6× improvement in the total RF output power of GaN power amplifiers. These demonstrations provide near-term validation of the large improvement in output power gained through embedded cooling and confirm the potential for well above a 6× improvement in GaN power amplifier output power to the electrical, rather than thermal, limits of GaN.

Rethinking the role of the state in technology development: DARPA and the case for embedded network governance

This paper explores the role of the state in re-architecting social networks and thereby new technology directions in the United States. It draws on a case study of DARPA's Microsystems Technology Office from 1992 to 2008. Leveraging one of the most radical directorships in DARPA's history, I argue that the perceived “death” of DARPA under Tony Tether was because past analyses, by focusing on the organization's culture and structure, overlooked a set of lasting, informal institutions among DARPA program managers. I find that despite significant changes in the recipients and outcomes of DARPA attentions, these same institutions for directing technology were in place both before and during Tether's directorship. Drawing on these results, I suggest that we must add to technology policy-making a new option— embedded network governance.

A New Wave of Innovation in Micro-Technology for Positioning, Navigation, and Timing (μPNT)

Inertial Measurement Units (IMUs) have been the central elements of stand-alone navigation and flight control systems for a variety of platforms, including aircraft, missiles, and land and marine vehicles. Miniaturization of IMUs has always been desirable because smaller size and lower weight opens up opportunities to carry additional payload or fuel, and perhaps enable new applications. Current inertial systems, however, do not meet the performance, size, weight, and cost requirements associated with many emerging DoD applications, including those needed for personal navigation, unmanned air/underwater vehicles, and autonomous robotic platforms. This presentation will discuss the growing interest within the Microsystems Technology Office (MTO) of the Defense Advanced Research Projects Agency (DARPA) in the development of a miniature, self-sufficient navigation system that might be realized through deep integration of timing, inertial navigation units, and other non-inertial sensors. A new wave of innovation is underway bringing to life revolutionary ideas and technologies in micro-fabrication, packaging, ultra-low-power electronics, innovative algorithms, never-before-explored architectures, and exploitation of new integration paradigms.

HIGH-SPEED, LOW-POWER DIGITAL AND ANALOG CIRCUITS IMPLEMENTED IN IBM SiGe BiCMOS TECHNOLOGY

Under the auspices of Defense Advanced Research Project Agency's Microsystems Technology Office (DARPA/MTO) Low Power Electronics Program, the Mayo Foundation Special Purpose Processor Development Group is exploring ways to reduce circuit power consumption, while maintaining or increasing functionality, for existing military systems. Applications presently being studied include all-digital radar receivers, electronic warfare receivers, and other types of digital signal processors. One of the integrated circuit technologies currently under investigation to support such military systems is the IBM Corporation silicon germanium (SiGe) BiCMOS process. In this paper, design methodology, simulations and test results from demonstration circuits developed for these applications and implemented in the IBM SiGe BiCMOS 5HP (50 GHz fT HBTs with 0.5 μm CMOS) and 7HP (120 GHz fT HBTs with 0.18 μm CMOS) technologies will be presented.