Lab on an end: Micromanipulation using the acoustohydrodynamic pillar array as an end effector

The concept of microfluidics has shown considerable promise for advancing chemistry, diagnostics, and biology. However, there have been no guaranteed routes of microfluidics that can achieve widespread adoption in mainstream chemistry and biomedical research. Inspired by the cooperative multiple cilia of biological organisms and tissues to generate flow, we propose an open microfluidic platform, lab on an end (LoE), to pump spatially and temporally continuous flow for multifunctional micromanipulation with the acoustohydrodynamic pillar array as an end effector. LoE brings together the micromanipulation of individual entities, liquid operations, and cell processing onto an acoustic end effector. These operations are mainly driven by acoustic radiation and two unique frequency-dependent microstreaming profiles: out-of-plane vortex near a single pillar and in-plane transmission flow surrounding the entire pillar array. Applications in embryo engineering, local morphological phenotyping of Caenorhabditis elegans for neuron research, efficient chemical reactions, and multifunctional cell processing indicate that the LoE could potentially lead to breakthroughs in understanding and using microfluidics. Its capability of integrating multiple sequential processes, inherent high accessibility, easy use, and low cost provide an end-to-end solution to mainstream chemistry and biomedical research.