Technique - (22) Optical tweezers / laser trapping

Type: Experimental

Description: Focused laser beam trapping for force measurement and biophysical manipulation.

Department(s)/lab(s): Physics & Astronomy – Biophysics | Jones Lab (Optical Tweezers Biophysics) @ UCL
Summary:

Jones's group develops optical tweezers instrumentation for biological applications. Research directions: (1) Single-cell mechanics β€” using optical traps to apply calibrated forces to cells and measure viscoelastic properties relevant to cancer invasion and immune response; (2) Motor protein biophysics β€” measuring force-velocity curves of kinesin/myosin motors at the single-molecule level; (3) Optical sorting β€” holographic optical tweezers for cell sorting by mechanical phenotype; (4) Instrument development β€” fast-switching AOD-based traps, quantitative phase imaging combined with force measurement. Sensitive to pN forces, combining biosensing with fundamental biophysics.

Department(s)/lab(s): D-ITET – Photonics Laboratory | Photonics Laboratory (Novotny Group) @ ETH Zurich
Summary:

Novotny leads the Photonics Lab with a primary focus on levitodynamics. Research directions: (1) Ground-state cooling of levitated nanoparticles β€” demonstrated quantum control and motional ground state cooling of silica nanospheres in cryogenic free space (Nature 2021) and all 6 degrees of freedom simultaneously via coherent scattering (Nature Physics 2023); (2) Quantum delocalization and matter-wave interference of levitated nanoparticles (arXiv 2408.01264, 2024); (3) Cavity-mediated long-range interactions between multiple levitated nanoparticles, enabling collective quantum sensing arrays; (4) Optical cold damping, measurement-free coherent feedback (PRL 2025); (5) 2D optoelectronics β€” graphene/hBN/TMD-based laser detectors and modulators. Heavily cited levitodynamics review (Science 2021, joint with Quidant). Group feeds into applications in quantum-limited force sensing and macroscopic quantum tests.

Department(s)/lab(s): D-MAVT – Nanophotonic Systems Laboratory | Nanophotonic Systems Laboratory (Quidant Group) @ ETH Zurich
Summary:

Quidant leads the Nanophotonic Systems Laboratory, developing hybrid integrated levitation platforms combining optical and RF fields. Research directions: (1) Measurement-free coherent optical feedback cooling of levitated nanoparticles (PRL 2025, phonon occupations ~100s); (2) Quantum sensing applications β€” ultra-sensitive force/acceleration sensing, directional dark matter detection with levitated sensors; (3) Meta-atom levitation β€” Mie-resonance high-permittivity particles in optical traps for extreme light-matter interaction; (4) Optofluidics β€” structured light for photothermal fluid control; (5) Cancer phototherapy β€” photothermal nanoparticle applications. Pioneer in nanoplasmonic tweezers, thermoplasmonics, and on-chip biosensing. Key co-author of Science levitodynamics review (2021).

Department(s)/lab(s): School of Physics | Reece Optical Trapping and Nanophotonics Laboratory @ UNSW
Summary:

Reece runs UNSW's optical trapping and nanophotonics laboratory. The group combines optical tweezers with spectroscopy and microfluidics to characterise individual nanoparticles and cells: trapping and spectroscopically interrogating plasmonic core-satellite assemblies (with Gooding and Tilley), measuring single-cell mechanics, and building porous-silicon and photonic-crystal resonant structures for label-free biosensing where the analyte shifts a cavity resonance. Positioned against the established body of NV-ensemble quantum sensing work β€” DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity β€” optical trapping is the standard way to hold a nanoscale sensor β€” including a nanodiamond hosting an NV ensemble at pT/sqrt(Hz) β€” at a controlled position inside a cell or fluid, and levitated-nanodiamond spin-mechanics is an active field that this group's capabilities map onto almost exactly. Strong practical fit for a bio-oriented quantum sensing candidate.

Department(s)/lab(s): Biochemistry and Molecular Biology | Rock Lab @ UChicago
Summary:

Rock builds custom single-molecule fluorescence microscopes and optical tweezers to directly watch individual myosin motors move along the actin cytoskeleton in vitro and in living cells, quantifying motor stoichiometry, force generation, and navigation rules that organize cell shape and motility. Where NV-ensemble quantum sensors read out spin ensembles magnetically at pT/sqrt(Hz) sensitivity via DEER/NMR/T1 protocols, Rock's approach achieves single-fluorophore and single-motor mechanical/positional resolution using all-optical single-molecule methods.

Department(s)/lab(s): Medicine | Rueda Single-Molecule Imaging Group @ Imperial
Summary:

Rueda leads a single-molecule imaging group (jointly at Imperial and the MRC London Institute of Medical Sciences) that combines single-molecule FRET, fluorogenic RNA aptamer imaging and optical tweezers to reveal the structural dynamics of RNA folding/splicing, CRISPR-Cas9 target search and off-target activity, and chromatin-remodelling complexes; the aptamer-imaging technology has been spun out as the startup Irida.

Department(s)/lab(s): Chemistry | Scherer Lab @ UChicago
Summary:

Uses single-molecule spectroscopy, optical trapping, and advanced imaging to study nanoscale systems. Directions: (1) orientation-resolved single-molecule spectroscopy using polarization-controlled excitation and detection; (2) optical trapping of individual nanoparticles and viruses to study force-dependent dynamics; (3) plasmon-enhanced single-molecule detection and imaging beyond diffraction limit; (4) ultrafast spectroscopy of nanoscale energy transfer.

Department(s)/lab(s): PME | Squires Lab @ UChicago
Summary:

Research centers on manipulating and measuring single molecules with quantum-level precision. Primary platform: ABEL trap (Anti-Brownian ELectrokinetic trap) for single-molecule confinement in free solution without surface tethering, enabling measurement of spectroscopic identity, molecular dynamics, and nanoscale energy transfer at femtomolar concentrations. Also develops orientation-resolved single-molecule imaging and single-molecule FRET for photoadaptation in photosynthetic systems and nanoscale immune cell signaling. QuBBE member. PhD Physics UChicago; joined 2024.

Department(s)/lab(s): Electrical & Electronic Engineering – Photon Science Institute | Quantum Engineering Lab (Vijayan Group) @ Manchester
Summary:

Vijayan leads the Quantum Engineering Lab at Manchester's Photon Science Institute, focusing on levitated optomechanics. Key results: (1) Programmable cavity-mediated long-range interactions between two levitated nanoparticles via coherently scattered photons (Nature Physics 2024, ETH Zurich/Innsbruck collaboration before Manchester); (2) Ground-state cooling of nanospheres and building toward quantum superpositions; (3) Quantum sensing with levitated systems β€” ultra-sensitive force/acceleration detectors; dark matter searches with nanoparticle momentum transfer detection (QTFP-funded collaboration with Darren Price); (4) Multi-particle quantum arrays. Royal Society University Research Fellow. Currently advertising PhD positions in quantum sensing with levitated optomechanical systems. Collaborates with Novotny (ETH), Romero-Isart (Innsbruck), and Millen (King's College London).

Department(s)/lab(s): Physics & Astronomy – Photon Science Institute | Waigh Group (Biophysics and Soft Matter) @ Manchester
Summary:

Waigh's group applies advanced optical and biophysical techniques to study complex biological fluids and single molecules. Research directions: (1) Microrheology β€” diffusing wave spectroscopy and optical trapping microrheology to measure viscoelastic properties of biopolymer networks and cytoplasm; (2) Antibody / protein dynamics β€” tracking single-molecule diffusion of antibodies and receptors in complex biological environments using fluorescence; (3) Non-linear flows of antibodies β€” studying anomalous diffusion and aggregation of therapeutic antibodies; (4) Neutron and X-ray scattering β€” structural characterization of complex biofluids at PSI facilities. Bridges soft matter physics and single-molecule biosensing.