Ward L. Johnson (Fed)

Ward Johnson is a physicist with a background that includes innovative acoustic metrology and effects of nanoscale defect dynamics and material structure on macroscopic vibration. He is a graduate of the Physics Department of the University of Illinois at Urbana-Champaign, with PhD research focused on anelastic effects of radiation-induced point defects in semiconductors. In 1987, he joined the Metallurgy Division of NIST in Gaithersburg and, in 1994, transferred to the former Materials Reliability Division in Boulder, which is now part of the Applied Chemicals and Materials Division. His work at NIST has included development and application of methods for characterizing dynamic elastic, anelastic, and/or nonlinear properties of metals, piezoelectrics, and semiconductors and the effects of microscale and nanoscale defects on these properties using resonant acoustics, pulsed-laser ultrasonics, and Brillouin light scattering. It has also included the invention of resonant-acoustic devices and methods for measuring the viscosity of fluids in pipes and sensing mechanical fluctuations of bacteria and effects of antibiotics on these fluctuations. 

Current Research

Current research is primarily focused on the development of methods for sensing performance-degrading defects in additively manufactured (AM) alloys through measurements of resonant acoustic nonlinearity and loss. This research aims to establish a nondestructive acoustic technique for rapidly evaluating the quality of AM parts in industrial settings.  

Additional information on current research:

Project webpages:
Additive Manufacturing Fatigue and Fracture

Resonating Platforms for Microbial, Environmental, and Materials Sensing

NIST News articles:
New NIST Method May Find Elusive Flaws in Medical Implants and Spacecraft

NIST’s Quick Test May Speed Antibiotic Treatment and Combat Drug Resistance