MIRTHE is a National Science Foundation Engineering Research Center headquartered at Princeton University, with partners City College New York, Johns Hopkins University, Rice, Texas A&M, and the University of Maryland-Baltimore County. The center encompasses a world-class team of engineers, chemists, physicists, environmental and bio-engineers, and clinicians. MIRTHE's goal is to develop Mid-Infrared (£ - 3-30 µm) optical trace gas sensing systems based on new technologies such as quantum cascade lasers or quartz-enhanced photo-acoustic spectroscopy, with the ability to detect minute amounts of chemicals found in the environment or atmosphere that are emitted from spills, combustion, or natural sources, or exhaled. Through its fundamental research and prototyping in materials, sources, detectors, sensing systems, and applications testbeds, MIRTHE addresses a broad range of technologies and industry sectors--semiconductors, test and measurement, medical equipment manufacturers, chemical and petrochemical, and homeland security--as well as government labs and hospitals. MIRTHE provides interdisciplinary and practice-oriented education for a diverse U.S. workforce and seeks to educate the public about chemical sensing with applications in environment, homeland security, and health.