Selected Applications
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Development of a Micromanipulator with an Haptic Interface
M. A. Srinivasan of MIT, USA and UCL, London, with support from TUM-IAS, Munich, has developed a micromanipulator with an haptic interface to enable manual exploration, manipulation, and assembly of micro-structures. In collaboration with A. Schmid of UCL, London, S. Thalhammer of Helmholtz Zentrum, Munich, and R. Yechangunja of Yantric, Inc., USA, he has demonstrated manual grasping and moving of 10 to 100 µ m sized objects with direct haptic feedback of the gripping force in real-time, so that the objects can be placed in three dimensions with nanometer precision [ 1 ].
A force-sensing microgripper with 100 µ m opening is mounted on an AN- Pxyz101 / NUM stack of attocube’ s closed loop positioners. Measured forces by the microgripper in the micro-Newton range are scaled up and exerted on the operator’ s fingers through a haptic interface.
[ 1 ] A. Schmid, R. Yechangunja, S. Thalhammer, and M. A. Srinivasan, Proceedings of the IEEE Haptics Symp., 517-522( 2012).( Images are courtesy of A. Schmid, S. Thalhammer, and M. A. Srinivasan)
Controlling Electron Emission in Space and Time
The dynamics of electrons emitted from a sharp tungsten tip triggered by femtosecond laser pulses have been investigated. The setup shown to the left is situated in an UHV chamber at p = 10-10 mbar pressure. A xyz positioning stack enables precision alignment of the tip. Photoelectron spectra are recorded while the phase between carrier wave and intensity envelope is varied in small steps. The lower figure shows two electron spectra, recorded with a phase difference of 180 degrees. In a), pronounced peaks are visible caused by interference of two electron wave packets emitted during subsequent optical cycles. In b), no peak structure is visible; only one electron wave packet contributes. This energy domain effect allows conclusions about the time dynamics of the electrons. By shaping the laser electric field with the carrier-envelope phase, the dynamics of the electrons can be controlled with attosecond precision. The presented system enables control over photoelectrons from a metal tip in space( nanometer scale) and time( attosecond scale).
( The data was kindly provided by M. Krüger, M. Schenk, and P. Hommelhoff, Max Planck Institute of Quantum Optics, Garching, Germany.) attoMOTION
Piezo-based Nano Drives