Active holographic tweezers based on spiraling interdigitated transducers

Recently, our team demonstrated the selective manipulations of microparticles [Baudoin et al., Sci. Adv. 5, eaav1967 (2019)] and cells [Baudoin et al., Nat. Commun. 11, 4244 (2020)] in a standard microscopy environment with active holographic tweezers based on spiraling interdigitated transducers. In this talk, we will present (i) the ultra-high frequency (250 MHz) selective manipulation of 4 μm beads with nanoNewton forces and (ii) first results on the the 3D manipulation of particles and in particular their axial displacement without any motion of the transducer, by tuning the driving frequency [Gong et al., Phys. Rev. Appl. 16, 024034 (2021)]. We will also introduce a new mixed finite element/angular spectrum code, which enables to understand the underlying physic and opens perspectives to improve the tweezers design.