Acoustic actuated fluorescence activated sorting of microparticles

Abstract

In this paper, we present a fluorescence activated sorter realized in a continuous flow microfluidic chip. Sorting is achieved by deflecting a focused particle stream with short acoustic bursts (2.5 ms), in a fluorescence activated configuration. The system utilizes two-dimensional acoustic pre-focusing, using a single actuation frequency, to position all particles in the same fluid velocity regime at flow rates up to 1.7 mL min(-1). Particles were sorted based on their fluorescence intensities at throughputs up to 150 particles s(-1). The highest purity reached was 80% when sorting at an average rate of 50 particles s(-1). The average recovery of a sort was 93.2 ± 2.6%. The presented system enables fluorescence activated cell sorting in a continuous flow microfluidic format that allows aseptic integration of downstream microfluidic functionalities, opening for medical and clinical applications.

Charge and topography patterned lithium niobate provides physical cues to fluidically isolated cortical axons

“…29 The results point to promising research directions exploiting LiNbO 3 as a neural substrate. Potentially, these can be combined with further control and sensing capabilities afforded by the photonic and piezoelectric properties of this material, already widely used for the nonlinear optical frequencyconversion of conventional lasers and to generate standing 31 and traveling 32 surface acoustic waves for sorting particles or cells in flow channels. Moreover, the topography patterning and microfluidic integration capabilities demonstrated with this work indicate LiNbO 3 as a promising material template for developing highly complex in vitro neuron culture devices, which allow controlling not only the surface topography but also the local chemical microenvironment.…”

Focusing of sub-micrometer particles and bacteria enabled by two-dimensional acoustophoresis

“…The use of two-dimensional focusing has previously only been explored for particles larger than 5 μm in diameter. 25,26,[33][34][35] In contrast to the case with one-dimensional standing acoustic waves, the simultaneous excitation of two orthogonal resonances generates an acoustic streaming velocity field that does not counteract the primary radiation force. A numerical model that predicts a streaming field with essentially a single large vortex centered in the cross section of the channel, in agreement with experimental data, is also presented.…”

Acoustofluidic harvesting of microalgae on a single chip

“…18,32 In case of a SAW-based device, acoustic waves are generated by inter-digitated transducers (IDTs) patterned on a piezoelectric plate at 10-1000 MHz. 35 In the device, a microfluidic chamber or channel is placed on the piezoelectric plate for the manipulation of particles in the channel. Comparing the two devices, the BAW-based device is more efficient in dealing with biological cells and similarly sized particles because of the wider frequency range of BAWs.…”