Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

Multiplying optical tweezers force using a micro-lever

Open Access Open Access

Abstract

This study presents a photo-driven micro-lever fabricated to multiply optical forces using the two-photon polymerization 3D-microfabrication technique. The micro-lever is a second class lever comprising an optical trapping sphere, a beam, and a pivot. A micro-spring is placed between the short and long arms to characterize the induced force. This design enables precise manipulation of the micro-lever by optical tweezers at the micron scale. Under optical dragging, the sphere placed on the lever beam moves, resulting in torque that induces related force on the spring. The optical force applied at the sphere is approximately 100 to 300 pN, with a laser power of 100 to 300 mW. In this study, the optical tweezers drives the micro-lever successfully. The relationship between the optical force and the spring constant can be determined by using the principle of leverage. The arm ratio design developed in this study multiplies the applied optical force by 9. The experimental results are in good agreement with the simulation of spring property.

©2011 Optical Society of America

Full Article  |  PDF Article
More Like This
Optically driven Archimedes micro-screws for micropump application

Chih-Lang Lin, Guy Vitrant, Michel Bouriau, Roger Casalegno, and Patrice L. Baldeck
Opt. Express 19(9) 8267-8276 (2011)

Force detection in optical tweezers using backscattered light

J. H. G. Huisstede, K. O. van der Werf, M. L. Bennink, and V. Subramaniam
Opt. Express 13(4) 1113-1123 (2005)

Hybrid optical tweezers for dynamic micro-bead arrays

Yoshio Tanaka, Shogo Tsutsui, Mitsuru Ishikawa, and Hiroyuki Kitajima
Opt. Express 19(16) 15445-15451 (2011)

Cited By

Optica participates in Crossref's Cited-By Linking service. Citing articles from Optica Publishing Group journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (9)

Fig. 1
Fig. 1 Details of TPP 3D-microfabrication: the interior of the microscope frame, the enlarged sample, and the voxel-based element.
Fig. 2
Fig. 2 AUTOCAD figures of a lever-beam with a spring. Left: the 3D-structure and enlarged portion of a lever beam with an “H” cross-section. Right: arm ratios (r1, r2, r3).
Fig. 3
Fig. 3 Micro-lever product (arm ratio: 2, 2.5, 3): (a) a SEM photo of a micro-lever, (b) a micro-lever with a spring observed by transmission with an optical microscope.
Fig. 4
Fig. 4 The relationship between the optical exerted force and laser power of different sphere sizes.
Fig. 5
Fig. 5 Demonstration of the typical rotation of a beam when the pivot is trapped by optical tweezers.
Fig. 6
Fig. 6 Demonstration of photo-driven micro-lever: optical force is applied at the sphere to pull (right) or compress (left) the spring.
Fig. 7
Fig. 7 The dependence of △xoptic when the optical force is increased in two directions: compression and pulling.
Fig. 8
Fig. 8 (a) a micro-lever (arm ratio: 3, 6, 9) with a spring observed by transmission with an optical microscope (b) The dependence of △xoptic when the optical force for arm ratios 3, 6, and 9 are increased.
Fig. 9
Fig. 9 The relationship diagram of the optical force (Foptic), induced force (Fspring), displacements of the sphere (△xoptic) and joint (△xspring), and the arm ratio (l1 + l2)/l1

Equations (3)

Equations on this page are rendered with MathJax. Learn more.

k exp = F spring Δ x spring = r F optic 1 r Δ x optic = r 2 (Δ x optic / F optic )
k the = G d 4 8 D 3 N
δ= P L 3 3EI
Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All rights reserved, including rights for text and data mining and training of artificial technologies or similar technologies.