John. A. Rogers

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The air-gap field-effect technique enabled realization of the intrinsic (not limited by static disorder) polaronic transport on the surface of rubrene (C42H28) crystals over a wide temperature range. The signatures of this intrinsic transport are the anisotropy of the carrier mobility, mu, and the growth of mu with cooling. Anisotropy of mu vanishes in the(More)
Gate-modulated transport through partially aligned films of single-walled carbon nanotubes (SWNTs) in thin film type transistor structures are studied experimentally and theoretically. Measurements are reported on SWNTs grown by chemical vapor deposition with systematically varying degrees of alignment and coverage in transistors with a range of channel(More)
This letter introduces a class of tunable microfluidic fiber device that uses molded plastic microchannels and electrowetting pumps. It demonstrates the application of this type of system to dynamically adjustable narrow-band and wide-band all-fiber filters. Compact size, low-cost fabrication procedures, low-power ( 1 mW) consumption, nonmechanical(More)
J. Song, Y. Huang, J. Xiao, S. Wang, K. C. Hwang, H. C. Ko, D.-H. Kim, M. P. Stoykovich, and J. A. Rogers Department of Mechanical and Aerospace Engineering, University of Miami, Coral Gables, Florida 33146, USA Department of Civil and Environmental Engineering, Northwestern University, Evanston, Illinois 60208, USA Department of Mechanical Engineering,(More)
We have observed the Hall effect in the field-induced accumulation layer on the surface of single-crystal samples of a small-molecule organic semiconductor rubrene. The Hall mobility muH increases with decreasing temperature in both the intrinsic (high-temperature) and trap-dominated (low-temperature) conduction regimes. In the intrinsic regime, the density(More)
The phase separation of ultrathin polymer-blend films of polystyrene and polybutadiene on microcontact printed alkanethiol patterns with hydrophobic and hydrophilic end groups (2CH3 and 2COOH! is investigated by atomic force microscopy. Simulations suggest that the phase-separation morphology can be controlled through patterns that modulate the(More)
The analytical solution is obtained for a semi-infinite linear elastic solid with a sinusoidal, “wavy” surface profile subject to applied strain. The amplitude A of a deformed wavy surface is related to the initial amplitude A0 and the applied strain a through the simple expression A A0 1 a . This relation is confirmed independently by finite element(More)
Electronic systems that use rugged lightweight plastics potentially offer attractive characteristics (low-cost processing, mechanical flexibility, large area coverage, etc.) that are not easily achieved with established silicon technologies. This paper summarizes work that demonstrates many of these characteristics in a realistic system: organic active(More)
Electronic systems that offer elastic mechanical responses to high strain deformation are of growing interest due to their ability to enable new applications whose requirements are impossible to satisfy with conventional wafer-based technologies. This article reviews the mechanics of stretchable inorganic materials on compliant substrates. Specifically,(More)
We describe a method of imaging the intensity profiles of light in near-field lithographic experiments directly by using a sensitive photoresist. This technique was applied to a detailed study of the irradiance distribution in the optical near field with contact-mode photolithography carried out by use of elastomeric phase masks. The experimental patterns(More)