| 1. |
- Asavei, T., et al.
(författare)
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Engineering Optically Driven Micromachines. - art. no. 703816
- 2008
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Ingår i: Optical Trapping and Optical Micromanipulation V. - 9780819472588 ; 7038, s. 3816-3816
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Konferensbidrag (refereegranskat)abstract
- Optical forces and torques acting on microscopic objects trapped in focussed laser beams promise flexible methods of driving micromachines through a microscope cover slip or even a cell wall. We are endeavouring to engineer special purpose micro-objects for a range of tasks. Colloidal self assembly of calcium carbonate provides birefringent spheres which can exert considerable torque, while two photon polymerisation allows us to fabricate objects of arbitrary shape that can be designed to exchange both spin and orbital angular momentum. Numerical calculations of forces and torques can allow an optimal design, and optical measurements provide us with certain knowledge of the forces and torques which are actually exerted.
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| 2. |
- Engström, David, 1976, et al.
(författare)
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Steering accuracy of a spatial light modulator-based single beam steerer: guidelines and limitations
- 2008
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Ingår i: SPIE Proceedings. - : SPIE. - 0277-786X .- 1996-756X. - 9780819472588
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Konferensbidrag (refereegranskat)abstract
- The positioning accuracy when a phase-only one dimensional spatial light modulator (SLM) is used for beam steering is limited by the number of pixels and their quantized phase modulation. Optimizing the setting of the SLM pixels individually can lead to the inaccuracy being a significant fraction of the diffraction limited spot size. This anomalous behaviour was simulated numerically, and experiments showed the same phenomena with very good agreement. However, by including an extra degree of freedom in the optimization of the SLM setting, we show that the accuracy can be improved by a factor proportional to the number of pixels in the SLM.
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| 3. |
- Roelofs, S. H., et al.
(författare)
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Calibration of trap stiffness and viscoelasticity in polymer solutions
- 2008
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Ingår i: Proc SPIE Int Soc Opt Eng. - : SPIE. - 9780819472588
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Konferensbidrag (refereegranskat)abstract
- We present an experimental demonstration of a method using optical tweezers proposed by Fischer and Berg-Sorensen for measuring viscoelasticity using optical tweezers. It is based on a sinusoidal oscillation of the liquid in combination with force measurements using optical tweezers. We verify the method by applying it to measurements in water, glycerol and polyethylene oxide (PEO).
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| 4. |
- Roelofs, S. H., et al.
(författare)
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Calibration of trap stiffness and viscoelasticity in polymer solutions - art. no. 703823
- 2008
-
Ingår i: Optical Trapping and Optical Micromanipulation V. - : SPIE. - 9780819472588 ; 7038, s. 3823-3823
-
Konferensbidrag (refereegranskat)abstract
- We present an experimental demonstration of a method using optical tweezers proposed by Fischer and Berg-Sorensen for measuring viscoelasticity using optical tweezers. it is based on a sinusoidal oscillation of the liquid in combination with force measurements using optical tweezers. We verify the method by applying it to measurements in water, glycerol and polyethylene oxide (PEO).
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