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