Drastic sensing enhancement using acoustic bubbles for surface-based microfluidic sensors

There is a high demand for ultrafast biosensors for industrial and public health applications. However, the performance of existing sensors is often limited by the slow mass transport process in traditional pressure-driven microfluidic devices. In this paper, we show for the first time that acoustic microbubbles trapped in prefabricated cavities in a micro-chamber are capable of enhancing fluid sample mixing that results in faster delivery of target species to the sensor surface. We demonstrate a drastic reduction of sensor response time (up to 21.3-fold) for surface-based nanosensors in presence of resonantly actuated microbubbles. The obtained results are valid in a wide pH (4-10) range and agree well with previous studies.