Versatile microchip utilising ultrasonic manipulation of microparticles

• This paper presents the concept and initial work on a microfluidic platform for bead-based analysis of biological sample. The core technology in this project is ultrasonic manipulation and trapping of particle in array configurations by means of acoustic forces. The platform is ultimately aimed for parallel multistep bioassays performed on biochemically activated microbeads (or particles) using submicrolitre sample volumes. A first prototype with three individually controlled particle trapping sites has been developed and evaluated. Standing ultrasonic waves were generated across a microfluidic channel by integrated PZT ultrasonic microtransducers. Particles in a fluid passing a transducer were drawn to pressure minima in the acoustic field, thereby being trapped and confined laterally over the transducer. It is anticipated that acoustic trapping using integrated transducers can be exploited in miniaturised total chemical analysis systems (μTAS), where e.g. microbeads with immobilised antibodies can be trapped in arrays and subjected to minute amounts of sample followed by a reaction, detected using fluorescence. Preliminary results indicate that the platform is capable of handling live cells as well as microbeads. A first model bioassay with detection of fluorescein marked avidin binding to trapped biotin beads has been evaluated

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Medicinteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Medical Engineering (hsv//eng)

Keyword

acoustic field

integrated PZT ultrasonic microtransducer

microfluidic channel

standing ultrasonic wave

submicrolitre sample volume

biochemically activated microbead

parallel multistep bioassay

biological sample

microparticle

versatile microchip

ultrasonic manipulation

acoustic trapping

chemical analysis system

immobilised antibody

fluorescein marked avidin binding

biotin bead

Publication and Content Type

kon (subject category)

ref (subject category)