Micromanipulation in microfluidics using optoelectronic and acoustic tweezing

The thesis introduces a concept for a unified platform that enables the use of acoustic and electric fields for particle manipulations in microfluidic environments. In particular, optoelectronic tweezing (OET), also known as light induced dielectrophoresis is fused with acoustic tweezing, also known as acoustophoresis, on a versatile system. The system can be divided into two individual physical units. The first one represents the OET unit which integrates light induced electric fields into a robust microfluidic chip. The OET chip not only operates as a device for electric field generation but also as a transverse resonator to confine acoustic fields. These fields are the result of travelling surface acoustic waves excited by a piezoelectric transducer which defines the second unit. The developed platform is applied to a range of applications such as particle trapping, transporting, focussing, sorting as well particle alterations in form of cell lysis and microbubble insonation