Cell detachment and label-free cell sorting using modulated surface acoustic waves (SAWs) in droplet-based microfluidics.

We present a droplet-based surface acoustic wave (SAW) system designed to viably detach biological cells from a surface and sort cell types based on differences in adhesion strength (adhesion contrast) without the need to label cells with molecular markers. The system uses modulated SAW to generate pulsatile flows in the droplets and efficiently detach the cells, thereby minimizing the SAW excitation power and exposure time. As a proof of principle, the system shows efficient sorting of HEK 293 from A7r5 cells based on adhesion contrast.

Integrated active mixing and biosensing using surface acoustic waves (SAW) and surface plasmon resonance (SPR) on a common substrate.

This article presents a device incorporating surface plasmon resonance (SPR) sensing and surface acoustic wave (SAW) actuation integrated onto a common LiNbO(3) piezoelectric substrate. The device uses Rayleigh-type SAW to provide active microfluidic mixing in the fluid above the SPR sensor. Validation experiments show that SAW-induced microfluidic mixing results in accelerated binding kinetics of an avidin-biotin assay.

An integrated hybrid interference and absorption filter for fluorescence detection in lab-on-a-chip devices.

We present a hybrid optical filter design that combines interference and absorbing components for enhanced fluorescence detection in miniaturized highly-integrated lab-on-a-chip devices. The filter is designed in such a way that the advantages of each technology are used to offset the disadvantages of the other. The filter is fabricated with microfabrication compatible processes and materials for monolithic integration with microelectronics and microfluidics devices.