Optical tweezers are very often used for measurement of piconewton range forces. Depending on the displacement of the trapped bead, the trap may become stiffer which causes considerable underestimation of the measured force. We have shown, both by theory and experiment, that such a stiffening occurs for beads larger than $0.5\mathrm{\mu m}$ in radius. For the first time, we have shown that the displacement at which the stiffening starts is size dependent and that the stiffening starts at higher forces for larger beads. We have shown that for the applications, which simultaneous force measurement and position sensing are on demand (such as biopolymer stretching), mid-range sized ( $\sim 1.5\mathrm{\mu m}$ in radius) beads could be the best choice.

© 2011 Optical Society of America

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Log in to access OSA Member Subscription

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Log in to access OSA Member Subscription

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Log in to access OSA Member Subscription

You do not have subscription access to this journal. Article level metrics are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Log in to access OSA Member Subscription

Related Journal Articles

• Calculation of spherical red blood cell deformation in a dual-beam optical stretcher (OE)
• A comparative study of living cell micromechanical properties by oscillatory optical tweezers (OE)
• Measuring the accuracy of particle position and force in optical tweezers using high-speed video microscopy (OE)
• Non-harmonic potential of a single beam optical trap (OE)
• Calibration of dynamic holographic optical tweezers for force measurements on biomaterials (OE)

Related Conference Papers

• Dynamically Adjustable Annular Laser Trapping for Sperm Chemotaxis Study
• Optical Trapping, Manipulation, and Sorting of Cells and Colloids in Microfluidic Systems with Diode Laser Bars
• Pulsed Optical Tweezers for Levitation and Manipulation of Stuck Biological Particles
• Interferometric Optical Sieve for Micro-Particle Segregation
• Observation of Orbital Angular Momentum Transfer to Particles Trapped in a Mathieu Beam