Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Light-driven microdrones

Abstract

When photons interact with matter, forces and torques occur due to the transfer of linear and angular momentum, respectively. The resulting accelerations are small for macroscopic objects but become substantial for microscopic objects with small masses and moments of inertia, rendering photon recoil very attractive to propel micro- and nano-objects. However, until now, using light to control object motion in two or three dimensions in all three or six degrees of freedom has remained an unsolved challenge. Here we demonstrate light-driven microdrones (size roughly 2 μm and mass roughly 2 pg) in an aqueous environment that can be manoeuvred in two dimensions in all three independent degrees of freedom (two translational and one rotational) using two overlapping unfocused light fields of 830 and 980 nm wavelength. To actuate the microdrones independent of their orientation, we use up to four individually addressable chiral plasmonic nanoantennas acting as nanomotors that resonantly scatter the circular polarization components of the driving light into well-defined directions. The microdrones are manoeuvred by only adjusting the optical power for each motor (the power of each circular polarization component of each wavelength). The actuation concept is therefore similar to that of macroscopic multirotor drones. As a result, we demonstrate manual steering of the microdrones along complex paths. Since all degrees of freedom can be addressed independently and directly, feedback control loops may be used to counteract Brownian motion. We posit that the microdrones can find applications in transport and release of cargos, nanomanipulation, and local probing and sensing of nano and mesoscale objects.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Illustration of the setup and microdrone actuation concept.
Fig. 2: Working principle of plasmonic nanomotors (simulation).
Fig. 3: Sketches of fundamental actuation patterns for two- and four-motor microdrones.
Fig. 4: Scanning electron (ae) and optical (f) micrographs of the fabricated structures.
Fig. 5: Actuation experiments of two-motor microdrones.
Fig. 6: Actuation experiments of four-motor microdrones.

Similar content being viewed by others

Data availability

The data for Fig. 5b are provided as source data with this paper. Other data supporting the conclusions of this study are available in the paper (including Supplementary Information).

Code availability

The codes used during this study are available from the corresponding authors upon reasonable request.

References

  1. Ashkin, A. Applications of laser radiation pressure. Science 210, 1081–1088 (1980).

    Article  CAS  Google Scholar 

  2. Cohen-Tannoudji, C. Manipulating atoms with photons. Phys. Scr. T76, 33–40 (1998).

    Article  CAS  Google Scholar 

  3. Ashkin, A. Atomic-beam deflection by resonance-radiation pressure. Phys. Rev. Lett. 25, 1321–1324 (1970).

    Article  CAS  Google Scholar 

  4. Ashkin, A. Acceleration and trapping of particles by radiation pressure. Phys. Rev. Lett. 24, 156–159 (1970).

    Article  CAS  Google Scholar 

  5. Maragò, O. M., Jones, P. H., Gucciardi, P. G., Volpe, G. & Ferrari, A. C. Optical trapping and manipulation of nanostructures. Nat. Nanotech. 8, 807–819 (2013).

    Article  Google Scholar 

  6. Aspelmeyer, M., Kippenberg, T. J. & Marquardt, F. Cavity optomechanics. Rev. Mod. Phys. 86, 1391–1452 (2014).

    Article  Google Scholar 

  7. Ilic, O., Went, C. M. & Atwater, H. A. Nanophotonic heterostructures for efficient propulsion and radiative cooling of relativistic light sails. Nano Lett. 18, 5583–5589 (2018).

    Article  CAS  Google Scholar 

  8. Šípová-Jungová, H., Andrén, D., Jones, S. & Käll, M. Nanoscale inorganic motors driven by light: principles, realizations, and opportunities. Chem. Rev. 120, 269–287 (2020).

    Article  Google Scholar 

  9. Wang, J., Xiong, Z. & Tang, J. The encoding of light-driven micro/nanorobots: from single to swarming systems. Adv. Intell. Syst. 3, 2000170 (2021).

    Article  Google Scholar 

  10. Xin, H. et al. Optical forces: from fundamental to biological applications. Adv. Mater. 32, 2001994 (2020).

    Article  CAS  Google Scholar 

  11. Kawata, S. & Tani, T. Optically driven Mie particles in an evanescent field along a channeled waveguide. Opt. Lett. 21, 1768–1770 (1996).

    Article  CAS  Google Scholar 

  12. Wang, K., Schonbrun, E. & Crozier, K. B. Propulsion of gold nanoparticles with surface plasmon polaritons: evidence of enhanced optical force from near-field coupling between gold particle and gold film. Nano Lett. 9, 2623–2629 (2009).

    Article  CAS  Google Scholar 

  13. Brzobohatý, O. et al. Experimental demonstration of optical transport, sorting and self-arrangement using a ‘tractor beam’. Nat. Photon. 7, 123–127 (2013).

    Article  Google Scholar 

  14. Búzás, A. et al. Light sailboats: laser driven autonomous microrobots. Appl. Phys. Lett. 101, 041111 (2012).

    Article  Google Scholar 

  15. Tanaka, Y. Y. et al. Plasmonic linear nanomotor using lateral optical forces. Sci. Adv. 6, eabc3726 (2020).

    Article  CAS  Google Scholar 

  16. Beth, R. A. Mechanical detection and measurement of the angular momentum of light. Phys. Rev. 50, 115–125 (1936).

    Article  Google Scholar 

  17. Friese, M. E. J., Nieminen, T. A., Heckenberg, N. R. & Rubinsztein-Dunlop, H. Optical alignment and spinning of laser-trapped microscopic particles. Nature 394, 348–350 (1998).

    Article  CAS  Google Scholar 

  18. Friese, M. E. J., Rubinsztein-Dunlop, H., Gold, J., Hagberg, P. & Hanstorp, D. Optically driven micromachine elements. Appl. Phys. Lett. 78, 547–549 (2001).

    Article  CAS  Google Scholar 

  19. Neale, S. L., MacDonald, M. P., Dholakia, K. & Krauss, T. F. All-optical control of microfluidic components using form birefringence. Nat. Mater. 4, 530–533 (2005).

    Article  CAS  Google Scholar 

  20. Tong, L., Miljković, V. D. & Käll, M. Alignment, rotation, and spinning of single plasmonic nanoparticles and nanowires using polarization dependent optical forces. Nano Lett. 10, 268–273 (2010).

    Article  CAS  Google Scholar 

  21. Lehmuskero, A., Ogier, R., Gschneidtner, T., Johansson, P. & Käll, M. Ultrafast spinning of gold nanoparticles in water using circularly polarized light. Nano Lett. 13, 3129–3134 (2013).

    Article  CAS  Google Scholar 

  22. He, H., Friese, M. E. J., Heckenberg, N. R. & Rubinsztein-Dunlop, H. Direct observation of transfer of angular momentum to absorptive particles from a laser beam with a phase singularity. Phys. Rev. Lett. 75, 826–829 (1995).

    Article  CAS  Google Scholar 

  23. Liu, M., Zentgraf, T., Liu, Y., Bartal, G. & Zhang, X. Light-driven nanoscale plasmonic motors. Nat. Nanotech. 5, 570–573 (2010).

    Article  CAS  Google Scholar 

  24. Yan, Z. & Scherer, N. F. Optical vortex induced rotation of silver nanowires. J. Phys. Chem. Lett. 4, 2937–2942 (2013).

    Article  CAS  Google Scholar 

  25. Galajda, P. & Ormos, P. Orientation of flat particles in optical tweezers by linearly polarized light. Opt. Express 11, 446–451 (2003).

    Article  Google Scholar 

  26. Rodrigo, P. J., Gammelgaard, L., Bøggild, P., Perch-Nielsen, I. R. & Glückstad, J. Actuation of microfabricated tools using multiple GPC-based counterpropagating-beam traps. Opt. Express 13, 6899–6904 (2005).

    Article  Google Scholar 

  27. Pollard, M. R. et al. Optically trapped probes with nanometer-scale tips for femto-Newton force measurement. New J. Phys. 12, 113056 (2010).

    Article  Google Scholar 

  28. Phillips, D. B. et al. An optically actuated surface scanning probe. Opt. Express 20, 29679–29693 (2012).

    Article  CAS  Google Scholar 

  29. Villangca, M. J., Palima, D., Bañas, A. R. & Glückstad, J. Light-driven micro-tool equipped with a syringe function. Light: Sci. Appl. 5, e16148 (2016).

    Article  CAS  Google Scholar 

  30. Lehmuskero, A., Li, Y., Johansson, P. & Käll, M. Plasmonic particles set into fast orbital motion by an optical vortex beam. Opt. Express 22, 4349–4356 (2014).

    Article  CAS  Google Scholar 

  31. Zhang, Y. et al. Plasmonic tweezers: for nanoscale optical trapping and beyond. Light: Sci. Appl. 10, 59 (2021).

    Article  CAS  Google Scholar 

  32. Chen, J., Ng, J., Lin, Z. & Chan, C. T. Optical pulling force. Nat. Photon. 5, 531–534 (2011).

    Article  CAS  Google Scholar 

  33. Song, J.-H., Shin, J., Lim, H.-J. & Lee, Y.-H. Optical recoil of asymmetric nano-optical antenna. Opt. Express 19, 14929–14936 (2011).

    Article  Google Scholar 

  34. Vercruysse, D. et al. Unidirectional side scattering of light by a single-element nanoantenna. Nano Lett. 13, 3843–3849 (2013).

    Article  CAS  Google Scholar 

  35. Andrén, D. et al. Microscopic metavehicles powered and steered by embedded optical metasurfaces. Nat. Nanotech. 16, 970–974 (2021).

    Article  Google Scholar 

  36. Wang, S. B. & Chan, C. T. Lateral optical force on chiral particles near a surface. Nat. Commun. 5, 3307 (2014).

    Article  CAS  Google Scholar 

  37. Rodríguez-Fortuño, F. J., Engheta, N., Martínez, A. & Zayats, A. V. Lateral forces on circularly polarizable particles near a surface. Nat. Commun. 6, 8799 (2015).

    Article  Google Scholar 

  38. Sukhov, S., Kajorndejnukul, V., Naraghi, R. R. & Dogariu, A. Dynamic consequences of optical spin–orbit interaction. Nat. Photon. 9, 809–812 (2015).

    Article  CAS  Google Scholar 

  39. Biagioni, P., Huang, J.-S. & Hecht, B. Nanoantennas for visible and infrared radiation. Rep. Prog. Phys. 75, 024402 (2012).

    Article  Google Scholar 

  40. Hoffmann, G., Huang, H., Waslander, S. & Tomlin, C. Quadrotor helicopter flight dynamics and control: theory and experiment. In Proc. AIAA Guidance, Navigation and Control Conference and Exhibit AIAA 2007-6461 https://doi.org/10.2514/6.2007-6461 (2007).

  41. Castillo, P., Lozano, R. & Dzul, A. Stabilization of a mini rotorcraft with four rotors. IEEE Control Syst. Mag. 25, 45–55 (2005).

    Article  Google Scholar 

  42. Lu, F., Lee, J., Jiang, A., Jung, S. & Belkin, M. A. Thermopile detector of light ellipticity. Nat. Commun. 7, 12994 (2016).

    Article  CAS  Google Scholar 

  43. Huang, J.-S. et al. Atomically flat single-crystalline gold nanostructures for plasmonic nanocircuitry. Nat. Commun. 1, 150 (2010).

    Article  Google Scholar 

  44. Ding, K., Ng, J., Zhou, L. & Chan, C. T. Realization of optical pulling forces using chirality. Phys. Rev. A 89, 063825 (2014).

    Article  Google Scholar 

  45. Cohen, A. E. & Moerner, W. E. Suppressing Brownian motion of individual biomolecules in solution. Proc. Natl. Acad. Sci. USA 103, 4362–4365 (2006).

    Article  CAS  Google Scholar 

  46. Shao, F. & Zenobi, R. Tip-enhanced Raman spectroscopy: principles, practice, and applications to nanospectroscopic imaging of 2D materials. Anal. Bioanal. Chem. 411, 37–61 (2019).

    Article  CAS  Google Scholar 

  47. Xavier, J., Vincent, S., Meder, F. & Vollmer, F. Advances in optoplasmonic sensors – combining optical nano/microcavities and photonic crystals with plasmonic nanostructures and nanoparticles. Nanophotonics 7, 1–38 (2018).

    Article  Google Scholar 

  48. Gao, W. & Wang, J. Synthetic micro/nanomotors in drug delivery. Nanoscale 6, 10486–10494 (2014).

    Article  CAS  Google Scholar 

  49. Johnson, P. B. & Christy, R. W. Optical constants of the noble metals. Phys. Rev. B 6, 4370–4379 (1972).

    Article  CAS  Google Scholar 

  50. Krauss, E. et al. Controlled growth of high-aspect-ratio single-crystalline gold platelets. Cryst. Growth Des. 18, 1297–1302 (2018).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

Financial support by the German Research Foundation (DFG grant no. HE5618/10-1) and the Volkswagen Foundation via an ‘Experiment!’ grant (both received by B.H.) is gratefully acknowledged.

Author information

Authors and Affiliations

Authors

Contributions

B.H. and X.W. conceived the project. X.W. designed the devices, structures and experiments. X.W., G.R. and T.F. performed numerical simulations. X.W. fabricated the samples and constructed the optical setup. X.W., R.E. and J.Q. carried out the optical measurements and analysed the data. X.W. and B.H. wrote the manuscript. All authors contributed to the discussion and manuscript preparation.

Corresponding authors

Correspondence to Xiaofei Wu or Bert Hecht.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Nanotechnology thanks Mikael Käll, Yun-Feng Xiao and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data

Extended Data Fig. 1 Fabrication of the gold nanomotors.

Upper row: Optical micrograph of a gold flake (a) and scanning helium ion micrographs of the nanomotor structures (b-d) after outline milling with focused helium ion beam. Lower row: Optical micrograph (a) and scanning electron micrographs (b-d) of the nanomotor structures after the gold flake is peeled off. The inset of the upper panel of a is an optical micrograph of the gold flake when its right corner is covered by a dried-out droplet of PVA solution. The outline of the gold flake and the boundary of the PVA droplet at the gold flake region are illustrate by the dashed lines in the lower panel of a.

Extended Data Fig. 2 Fabrication of the microdrone body.

a, Gold nanomotors are fabricated on top of a spin-coated HSQ layer on an ITO/glass substrate. b, An etching mask of HSQ with the same shape of the microdrone body but increased thickness is created in the first electron beam lithography (EBL) step. c, The bottom HSQ layer is etched through with buffered oxide etch (BOE). The top mask is also thinned down and the wet etching leads to an unwanted side profile. d, The sample is spin-coated with HSQ again and the final body with defined shape and dimensions is created in the second EBL step. In panels a-c, the top and bottom HSQ layers are presented in different colors for better illustration.

Extended Data Fig. 3 Transfer of microdrones to a water cell.

Reflection (a-c) and phase-contrast transmission (d) optical micrographs of microdrones of a sample at key steps of the transfer process. a, On the glass substrate after ITO etching. The microdrones have moved slightly after the etching. The inset shows the well-aligned array before ITO etching. The shiny dots and disk are gold markers for pattern alignment for electron beam lithography. b, A PMMA piece with the microdrones attached on the top. A zoom to the area indicated by the dashed rectangle is shown in the inset (same for c and d as well). It is seen that the microdrone array is right-left flipped as compared to a. c, A PVA piece with the microdrones attached on the top. The microdrone array is flipped again as compared to b. d, The microdrones are transferred to water. The water droplet has a volume of about 2.5 µL and is sandwiched between two glass coverslips with a spacer of PDMS (165 μm thick). Now the microdrones are seen as the swarm of dark dots. The air bubble to the right will disappear with time.

Extended Data Fig. 4 Schematic of the optical setup.

The inset to the left sketches the fact that both laser beams are focused by the lens to the back focal plane (BFP) of the top objective (for polarized light) to create unfocused light fields. Both 830 and 980 nm laser beams pass a polarizer (horizontal direction) positioned directly behind the laser diodes. The two light beams are overlapping after the dichroic mirror LP 900 nm. The polarization compensator is used to correct the influence of the dichroic mirror LP 900 nm to the linear polarization of the 980 nm beam. The components and the water cell are not to scale.

Supplementary information

Supplementary Information

Supplementary Figs. 1–5, Notes 1–3 and Videos 1–5.

Supplementary Video 1

Effect of the torque resulting from the transfer of the spin angular momentum of photons. Two types of microdrone with two identical motors are excited in the same light field of 830 nm. The two microdrones differ in the orientation of the motors, such that the two torque components on the right side of equation (1) have the same sign for one microdrone but have opposite signs for the other. As a result, the former microdrone rotates in the same direction as the circular polarization (orange arrow) with a higher speed, while the latter microdrone rotates in the direction opposite to the circular polarization with a slower speed.

Supplementary Video 2

Brownian motion of the microdrones inside the water cell after release when there is no driving light.

Supplementary Video 3

Actuation of two-motor microdrones. The original video has a frame rate of 100 fps, but is slowed down to 30 fps here. The parameters at the top are updated every six frames. The changing colour of the trajectories represents the progressing time. The positions of the motors (red points) are determined by fitting each of their images in the movie frames (dark spots) with a 2D elliptical Gaussian function. The centre of the microdrone and the orientation angles (yaw, pitch and roll) are extracted from the fitted motor coordinates.

Supplementary Video 4

Actuation of four-motor microdrones. The original video has a frame rate of 100 fps, but is slowed down to 30 fps here. The parameters at the top are updated every six frames. The changing colour of the trajectories represents the progressing time. The positions of the motors (red points) are determined by fitting each of their images in the movie frames (dark spots) with a 2D elliptical Gaussian function. The centre of the microdrone and the orientation angles (yaw, pitch and roll) are extracted from the fitted motor coordinates.

Supplementary Video 5

Continuous actuation of a four-motor microdrone in all three independent degrees of freedom.

Source data

Source Data Fig. 5

Statistical source data.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Wu, X., Ehehalt, R., Razinskas, G. et al. Light-driven microdrones. Nat. Nanotechnol. 17, 477–484 (2022). https://doi.org/10.1038/s41565-022-01099-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41565-022-01099-z

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing