Hundreds of millions of years of evolution resulted in hair-based flow sensors in terrestrial arthropods that stand out among the most sensitive biological sensors known. These tiny sensory hairs can move with a velocity close to that of the surrounding air at frequencies near their mechanical resonance, in spite of the low viscosity and low density of air. No man-made technology to date demonstrates comparable efficiency. Here we show that nanodimensional spider silk captures fluctuating airflow with maximum physical efficiency (Vsilk/Vair≈1) from 1Hz to 50kHz, providing an unparalleled means for miniaturized flow sensing. Our mathematical model shows excellent agreement with experimental results for silk with various diameters: 500nm, 1.6µm, 3µm. When a fiber is sufficiently thin, it can move with the medium flow perfectly due to the domination of forces applied to it by the medium over those associated with its mechanical properties. By modifying a spider silk to be conductive and transducing its motion using electromagnetic induction, we demonstrate a miniature, directional, broadband, passive, low cost approach to detect airflow with full fidelity over a frequency bandwidth that easily spans the full range of human hearing, as well as other mammals, birds, amphibians, and reptiles.
Distinguished Professor Ron Miles serves as chair of the Department of Mechanical Engineering. His research involves the diverse fields of mechanics, acoustics, vibrations, MEMS, neurobiology, and control systems to create advanced micro-acoustic sensors. These devices have applications in consumer electronics, lab instrumentation, automotive, hearing aids and other healthcare applications.
Dr. Miles has been with Binghamton's Department of Mechanical Engineering since 1989 and has served as the Director of Graduate Studies, Director of Undergraduate Studies, Associate Chair, Department Chair, Professor and currently as Distinguished Professor. He has also served as Associate Dean for Research in the Watson School. He currently serves as Associate Editor for the ASME Journal of Vibration and Acoustics. Ron Miles received a BS in Electrical Engineering from the University of California at Berkeley in 1976, and his MS and Ph.D. in mechanical engineering from the University of Washington. Beginning in 1977 he worked on structural acoustics and noise control at Boeing for eight years. He was an assistant research engineer and lecturer in the Department of Mechanical Engineering at UC Berkeley and a faculty fellow in the Structural Acoustics Branch at NASA Langley.
Dr. Miles has published over one hundred scholarly articles, presented over seventy invited lectures; holds over twenty United States and international patents; has received the University Award for Excellence in Teaching; the Chancellor's Award for Excellence in Teaching; the Research Foundation's Outstanding Inventor Award; the Chancellor's Award for Research in Science, Engineering and Medicine; the Research Foundation's Innovation, Creation and Discovery Award; the Research Foundation's 2005 First Patent Award; and was named Distinguished Professor in May 2011. His research team has included over 80 doctoral, masters and baccalaureate students with research funding over $17M from federal, state, corporate and charitable organizations.