Caltech
John E. Sader

John E. Sader

Research Professor of Aerospace and Applied Physics

John Sader uses his expertise in applied mathematics across a wide range of research areas, including atomic force microscopy, fluid mechanics, solid mechanics, fluid-structure interaction, rarefied gas dynamics, colloid science, plasmonics, and mass spectrometry.

A snapshot of some of John's research is below.

Atomic force microscopy

1. Sader method for the calibration of atomic force microscope cantilevers

Sample publications:

  • J. E. Sader, R. Borgani, C. T. Gibson, D. B. Haviland, M. J. Higgins, J. I. Kilpatrick, J. Lu, P. Mulvaney, C. J. Shearer, A. D. Slattery, P.-A. Thorén, J. Tran, H. Zhang, H. Zhang and T. Zheng, "A virtual instrument to standardise the calibration of atomic force microscope cantilevers", Review of Scientific Instruments, 87, 093711 (2016).
  • J. E. Sader, J. A. Sanelli, B. D. Adamson, J. P. Monty, X. Wei, S. A. Crawford, J. R. Friend, I. Marusic, P. Mulvaney and E. J. Bieske, "Spring constant calibration of atomic force microscope cantilevers of arbitrary shape", Review of Scientific Instruments, 83, 103705 (2012).
  • C. P. Green, H. Lioe, J. P. Cleveland, R. Proksch, P. Mulvaney and J. E. Sader, "Normal and torsional spring constants of atomic force microscope cantilevers", Review of Scientific Instruments, 75, 1988-1996 (2004).
  • J. E. Sader, J. W. M. Chon and P. Mulvaney, "Calibration of rectangular atomic force microscope cantilevers", Review of Scientific Instruments, 70, 3967-3969 (1999).

2. Sader-Jarvis method for force measurements using frequency-modulation atomic force microscopy

Sample publications:

  • J. E. Sader, B. D. Hughes, F. Huber and F. J. Giessibl, "Interatomic force laws that evade dynamic measurement", Nature Nanotechnology, 13, 1088-1091 (2018).
  • T. Uchihashi, M. J. Higgins, S. Yasuda, S. P. Jarvis, S. Akita and Y. Nakayama and J. E. Sader, "Quantitative force measurements in liquid using frequency modulation atomic force microscopy", Applied Physics Letters, 85, 3575-3577 (2004).
  • J. E. Sader and S. P. Jarvis, "Interpretation of frequency modulation atomic force spectroscopy in terms of fractional calculus", Physical Review B, 70, 012303 (2004).
  • J. E. Sader and S. P. Jarvis, "Accurate formulas for interaction force and energy in frequency modulation force spectroscopy", Applied Physics Letters, 84, 1801-1803 (2004).

Fluid-structure interaction

1. Linear response of cantilevered structures immersed in viscous fluid

Sample publications:

  • N. Shen, D. Chakraborty and J. E. Sader, "Frequency response of cantilevered plates of small aspect ratio immersed in viscous fluids", Journal of Applied Physics, 133, 034501 (2023).
  • C. A. Van Eysden and J. E. Sader, "Frequency response of cantilever beams immersed in a viscous fluid with applications to the atomic force microscope: Arbitrary mode order", Journal of Applied Physics, 101, 044908 (2007).
  • C. P. Green and J. E. Sader, "Torsional frequency response of cantilever beams immersed in viscous fluids with applications to the atomic force microscope", Journal of Applied Physics, 92, 6262-6274 (2002).
  • J. E. Sader, "Frequency response of cantilever beams immersed in viscous fluids with applications to the atomic force microscope", Journal of Applied Physics, 84, 64-76 (1998).

2. Suspended microchannel resonators for ultrasensitive measurement in liquid

Sample publications:

  • G. Katsikis, J. F. Collis, S. M. Knudsen, V. Agache, J. E. Sader and S. R. Manalis, "Inertial and viscous flywheel sensing of nanoparticles", Nature Communications, 12, 5099 (2021).
  • J. F. Collis, S. Olcum, D. Chakraborty, S. R. Manalis and J. E. Sader, "The measurement of Navier slip on individual nanoparticles in liquid", Nano Letters, 21, 4959-4965 (2021).
  • J. E. Sader, T. P. Burg and S. R. Manalis, "Energy dissipation in microfluidic beam resonators", Journal of Fluid Mechanics, 650, 215-250 (2010).
  • T. P. Burg, J. E. Sader and S. R. Manalis, "Nonmonotonic energy dissipation in microfluidic resonators", Physical Review Letters, 102, 228103 (2009).

3. Nonlinear dynamics of an inverted flag in a uniform stream

Sample publications:

  • J. S. Leontini and J. E. Sader, "The dynamics of a rigid inverted flag", Journal of Fluid Mechanics, 948, A47 (2022).
  • C. Huertas-Cerderia, A. Goza, J. E. Sader, T. Colonius and M. Gharib, "Dynamics of an inverted cantilever plate at moderate angles of attack", Journal of Fluid Mechanics, 909, A20 (2021).
  • J. E. Sader, C. Huertas-Cerdeira and M. Gharib, "Stability of slender inverted flags and rods in uniform steady flow", Journal of Fluid Mechanics, 809, 873-894 (2016).
  • J. E. Sader, J. Cossé, D. Kim, B. Fan and M. Gharib, "Large-amplitude flapping of an inverted-flag in a uniform steady flow – a vortex-induced vibration", Journal of Fluid Mechanics, 793, 524-555 (2016).

4. Nanoparticles immersed in Newtonian and non-Newtonian fluids

Sample publications:

  • B. Uthe, J. E. Sader and M. Pelton, "Optical measurement of the picosecond fluid mechanics of simple liquids generated by vibrating nanoparticles: A review", Reports on Progress in Physics, 85, 103001 (2022).
  • D. Chakraborty, B. Uthe, E. W. Malachosky, M. Pelton and J. E. Sader, "Viscoelasticity enhances nanometer-scale slip in gigahertz-frequency liquid flows", Journal of Physical Chemistry Letters, 12, 3449-3455 (2021).
  • M. Pelton, D. Chakraborty, E. Malachosky, P. Guyot-Sionnest and J. E. Sader, "Viscoelastic flows in simple liquids generated by vibrating nanostructures", Physical Review Letters, 111, 244502 (2013).
  • M. Pelton, J. E. Sader, J. Burgin, M. Liu, P. Guyot-Sionnest and D. Gosztola, "Damping of acoustic vibrations in gold nanoparticles", Nature Nanotechnology, 4, 492-495 (2009).

5. Autonomous propulsion of nanoparticles in acoustic fields

Sample publications:

  • J. F. Collis, D. Chakraborty and J. E. Sader, "Autonomous propulsion of nanorods trapped in an acoustic field – corrigendum", Journal of Fluid Mechanics, 935, E1 (2022).
  • J. F. Collis, D. Chakraborty and J. E. Sader, "Autonomous propulsion of nanorods trapped in an acoustic field", Journal of Fluid Mechanics, 825, 29-48 (2017).

Fluid mechanics

1. Plastic flow of yield stress materials

Sample publications:

  • E. M. Hinton, J. F. Collis and J. E. Sader, "The motion of a layer of yield-stress material on an oscillating plate", Journal of Fluid Mechanics, 959, A32 (2023).
  • E. M. Hinton, J. F. Collis and J. E. Sader, "A layer of yield-stress material on a flat plate that suddenly moves", Journal of Fluid Mechanics, 942, A30 (2022).
  • J. A. Chamberlain, S. Clayton, K. A. Landman and J. E. Sader, "Experimental validation of incipient failure of yield stress materials under gravitational loading", Journal of Rheology, 47, 1317-1329 (2003).
  • J. A. Chamberlain, J. E. Sader, K. A. Landman, D. J. Horrobin and L. R. White, "Incipient failure of a circular cylinder under gravity", International Journal of Mechanical Sciences, 44, 1779-1800 (2002).

2. Water bells formed by a jet impinging on a flat surface

Sample publications:

  • E. C. Button, J. F. Davidson, G. J. Jameson and J. E. Sader, "Water bells formed on the underside of a horizontal plate. Part 2. Theory", Journal of Fluid Mechanics, 649, 45-68 (2010).
  • G. J. Jameson, C. E. Jenkins, E. C. Button and J. E. Sader, "Water bells formed on the underside of a horizontal plate. Part 1. Experimental investigation", Journal of Fluid Mechanics, 649, 19-43 (2010).
  • G. J. Jameson, C. Jenkins, E. C. Button and J. E. Sader, "Water bells created from below", Physics of Fluids, 20, 091108 (2008).

3. Asymptotic analysis of the Boltzmann equation for unsteady gas flows

Sample publications:

  • N. Z. Liu, D. R. Ladiges, J. Nassios and J. E. Sader, "Acoustic flows in a slightly rarefied gas", Physical Review Fluids, 5, 043401 (2020).
  • D. R. Ladiges and J. E. Sader, "Variational method enabling simplified solutions to the linearized Boltzmann equation for oscillatory gas flows", Physical Review Fluids, 18, 053401 (2018).
  • J. Nassios and J. E. Sader, "High frequency oscillatory flows in a slightly rarefied gas according to the Boltzmann-BGK equation", Journal of Fluid Mechanics, 729, 1-46 (2013).
  • J. Nassios and J. E. Sader, "Asymptotic analysis of the Boltzmann-BGK equation for oscillatory flows", Journal of Fluid Mechanics, 708, 197-249 (2012).

4. Starting vortex generated by a moving body

Sample publication:

  • D. I. Pullin and J. E. Sader, "On the starting vortex generated by a translating and rotating flat plate", Journal of Fluid Mechanics, 906, A9 (2021).

Computational methods for gas flows

1. Lattice Boltzmann for unsteady gas flows (virtual time concept)

Sample publications:

  • Y. Shi, D. R. Ladiges and J. E. Sader, "Origin of spurious oscillations in lattice Boltzmann simulations of oscillatory noncontinuum gas flows," Physical Review E, 100, 053317 (2019).
  • Y. Shi, Y. W. Yap and J. E. Sader, "Lattice Boltzmann method for linear oscillatory non-continuum flows", Physical Review E, 89, 033305 (2014).
  • Y. Shi, P. L. Brookes, Y. W. Yap and J. E. Sader, "Accuracy of the lattice Boltzmann method for low-speed noncontinuum flows", Physical Review E, 83, 045701 (2011).
  • Y. Shi and J. E. Sader, "Lattice Boltzmann method for oscillatory Stokes flow with applications to micro- and nanodevices", Physical Review E, 81, 036706 (2010).

2. Monte Carlo methods for the unsteady linearized Boltzmann equation (using the virtual time concept)

Sample publications:

  • D. R. Ladiges and J. E. Sader, "Frequency-domain deviational Monte Carlo method for linear oscillatory gas flows", Physics of Fluids, 27, 102002 (2015).
  • D. R. Ladiges and J. E. Sader, "Frequency-domain Monte Carlo method for linear oscillatory gas flows", Journal of Computational Physics, 284, 351-366 (2015).

Nanomechanics and solid mechanics

1. Measuring the mechanical properties of nanowires using atomic force microscopy

Sample publications:

  • E. K. McCarthy, A. T. Bellew, J. E. Sader and J. J. Boland, "Poisson's ratio of individual metal nanowires", Nature Communications, 5, 4336 (2014).
  • B. Wen, J. E. Sader and J. J. Boland, "Mechanical properties of ZnO nanowires", Physical Review Letters, 101, 175502 (2008).
  • L. T. Ngo, D. Almecija, J. E. Sader, B. Daly, N Petkov, J. D. Holmes, D. Erts and J. J. Boland, "Ultimate-Strength Germanium Nanowires", Nano Letters, 6, 2964-2968 (2006).
  • A. Heidelberg, L. T. Ngo, B. Wu, M. A. Phillips, S. Sharma, T. I. Kamins, J. E. Sader and J. J. Boland, "A generalized description of the elastic properties of nanowires", Nano Letters, 6, 1101-1106 (2006).

2. Measuring the mechanical properties of nanoparticles using ultrafast laser spectroscopy

Sample publications:

  • C. Yi, P. D. Dongare, M.-N. Su, W. Wang, D. Chakraborty, F. Wen, W.-S. Chang, J. E. Sader, P. Nordlander, N. J. Halas and S. Link, "Vibrational coupling in plasmonic molecules", Proceedings of the National Academy of Sciences of the United States of America, 114, 11621-11626 (2017).
  • W.-S. Chang, F. Wen, D. Chakraborty, M.-N. Su, Y. Zhang, B. Shuang, P. Nordlander, J. E. Sader, N. J. Halas and S. Link, "Tuning the acoustic frequency of a gold nanodisk through its adhesion layer", Nature Communications, 6, 7022 (2015).
  • H. Petrova, C-H. Lin, M. Hu, J. Chen, A. R. Siekkinen, Y. Xia, J. E. Sader and G. V. Hartland, "Vibrational response of Au-Ag nanoboxes and nanocages to ultrafast laser-induced heating", Nano Letters, 7, 1059-1063 (2007).
  • M. Hu, X. Wang, G. V. Hartland, P. Mulvaney, J. P. Juste and J. E. Sader, "Vibrational response of nanorods to ultrafast laser induced heating: theoretical and experimental analysis", Journal of the American Chemical Society, 125, 14925-14933 (2003).

3. Mass spectrometry using nanomechanical sensors

Sample publications:

  • S. Stassi, G. De Laurentis, D. Chakraborty, K. Bejtka, A. Chiodoni, J. E. Sader and C. Ricciardi, "Large-scale parallelization of nanomechanical mass spectrometry with weakly-coupled resonators", Nature Communications, 10, 3647 (2019).
  • J. E. Sader, M. S. Hanay, A. P. Neumann and M. L. Roukes, "Mass spectrometry using nanomechanical systems: beyond the point-mass approximation", Nano Letters, 18, 1608-1614 (2018).
  • M. S. Hanay, S. I. Kelber, C. D. O'Connell, P. Mulvaney, J. E. Sader and M. L. Roukes, "Inertial imaging with nanomechanical systems", Nature Nanotechnology, 10, 339-344 (2015).
  • R. B. Karabalin, L. G. Villanueva, M. H. Matheny, J. E. Sader and M. L. Roukes, "Stress-induced variations in the stiffness of micro- and nanocantilever beams", Physical Review Letters, 108, 236101 (2012).

4. Nonlinearites in nanomechanics

Sample publications:

  • M. H. Matheny, L. G. Villanueva, R. B. Karabalin, J. E. Sader and M. L. Roukes, "Nonlinear mode-coupling in nanomechanical systems", Nano Letters, 13, 1622-1626 (2013).
  • L. G. Villanueva, R. B. Karabalin, M. H. Matheny, D. Chi, J. E. Sader and M. L. Roukes, "Nonlinearity in nanomechanical cantilevers", Physical Review B, 87, 024304 (2013).
  • R. B. Karabalin, L. G. Villanueva, M. H. Matheny, J. E. Sader and M. L. Roukes, "Stress-induced variations in the stiffness of micro- and nanocantilever beams", Physical Review Letters, 108, 236101 (2012).

5. Nonlinearities in deployable space structures

Sample publications:

  • J. E. Sader, M. Delapierre and S. Pellegrino, "Shear-induced buckling of a thin elastic disk undergoing spin-up", International Journal of Solid and Structures, 166, 75-82 (2019).
  • M. Delapierre, D. Chakraborty, J. E. Sader and S. Pellegrino, "Wrinkling of transversely loaded spinning membranes", International Journal of Solid and Structures, 139-140, 163-173 (2018).