Design and Use of Wafer Level Fluidic Packaging for Surface Acoustic Wave Sensors

We demonstrate the propagation of a Love mode acoustic wave in a thin SU8 epoxy layer coating a AT-cut quartz substrate: the resulting insertion losses are observed in the -35 to -40 dB range. We demonstrate the packaging of this device in a SU8 microfluidic system preventing liquids from covering the interdigitated transducer while defining the chemical reaction area in the region between the interdigitated transducer. We demonstrate the ability to chemically functionalize the SU8 layer with amine-ended groups. Finally, a time-resolved adsorption of small (600 daltons) organometallic molecules is presented for illustrating the detection sensitivity and selectivity of the resulting sensor working with analytes in aqueous solutions.