title: Nanomechanical motion ofEscherichia coliadhered to a surface.
abstract: Nanomechanical motion of bacteria adhered to a chemically functionalized silicon surface is studied by means of a microcantilever. A non-specific binding agent is used to attachEscherichia coli(E. coli) to the surface of a silicon microcantilever. The microcantilever is kept in a liquid medium, and its nanomechanical fluctuations are monitored using an optical displacement transducer. The motion of the bacteria couples efficiently to the microcantilever well below its resonance frequency, causing a measurable increase in the microcantilever fluctuations. In the time domain, the fluctuations exhibit large-amplitude low-frequency oscillations. In corresponding frequency-domain measurements, it is observed that the mechanical energy is focused at low frequencies with a 1/fα-type power law. A basic physical model is used for explaining the observed spectral distribution of the mechanical energy. These results lay the groundwork for understanding the motion of microorganisms adhered to surfaces and for developing micromechanical sensors for bacteria.
authors.affiliation: Department of Mechanical Engineering, Division of Materials Science and Engineering, and the Photonics Center, Boston University , Boston, Massachusetts 02215, USA.
authors.forename: C
authors.initials: C
authors.lastname: Lissandrello
authors.affiliation: Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Canary Center at Stanford for Cancer Early Detection, Stanford University School of Medicine , Palo Alto, California 94304, USA.
authors.forename: F
authors.initials: F
authors.lastname: Inci
authors.affiliation: Department of Mechanical Engineering, Virginia Polytechnic Institute and State University , Blacksburg, Virginia 24061, USA.
authors.forename: M
authors.initials: M
authors.lastname: Francom
authors.affiliation: Department of Mechanical Engineering, Virginia Polytechnic Institute and State University , Blacksburg, Virginia 24061, USA.
authors.forename: M R
authors.initials: MR
authors.lastname: Paul
authors.affiliation: Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Canary Center at Stanford for Cancer Early Detection, Stanford University School of Medicine , Palo Alto, California 94304, USA.
authors.forename: U
authors.initials: U
authors.lastname: Demirci
authors.affiliation: Department of Mechanical Engineering, Division of Materials Science and Engineering, and the Photonics Center, Boston University , Boston, Massachusetts 02215, USA.
authors.forename: K L
authors.initials: KL
authors.lastname: Ekinci