title: Fiber-optic trap-on-a-chip platform for probing low refractive index contrast biomaterials.
abstract: Dual-beam fiber trapping is a versatile technique for manipulating microparticles. We fabricate and evaluate the performance of a compact trap-on-a-chip design and demonstrate, for what we believe is the first time, trapping of low-contrast (m<1.005) lipid vesicles in solution. Counterpropagating fibers are fixed along the chip channel, and we calibrate the trap by optically displacing polystyrene microspheres from the trap center. Measured scattering forces are ~30-49 pN from each beam. Stable trapping and reversible deformation of lipid vesicles is demonstrated under femtonewton trapping forces. This chip has applications in probing a variety of soft biomaterials, such as biological cells, lipid membranes, and protein assemblies.
authors.affiliation: School of Engineering, University of California, Merced, California 95343, USA.
authors.forename: Tessa M
authors.initials: TM
authors.lastname: Piñón
authors.forename: Alessandro R
authors.initials: AR
authors.lastname: Castelli
authors.forename: Linda S
authors.initials: LS
authors.lastname: Hirst
authors.forename: Jay E
authors.initials: JE
authors.lastname: Sharping
mesh_terms: D001688:Biological Products / Q000032:analysis / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D008563:Membrane Lipids / Q000032:analysis / Q000737:chemistry*; D052898:Optical Tweezers; D012031:Refractometry / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D053835:Unilamellar Liposomes / Q000032:analysis / Q000737:chemistry*
chemical_list: D001688:Biological Products; D008563:Membrane Lipids; D053835:Unilamellar Liposomes