Liposomes have garnered significant attention owing to their favorable characteristics as promising carriers. Microfluidic based hydrodynamic flow focusing, or micro-mixing approaches enable precise control of liposome size during their synthesis due to the comparable size scale. However, current microfluidic approaches still have issues such as high flow rate dependency, complex chip structures, and ease of clogging. Herein, we present a novel microfluidic platform for size-tunable liposome synthesis based on an ultra-high-frequency acoustic resonator. By designing the shape and orientation of the acoustic resonator in the three-phase laminar flow, it combined the features of both hydrodynamic flow focusing and rapid micro-mixing. The distribution of lipid precursor solution in laminar flow and the mixing conditions could be regulated by the confined acoustic streaming vortex. We successfully synthesize liposomes with adjustable sizes and narrow size distributions. Notably, this platform regulates the product size by adjusting only the input power, which is less dependent on the flow rate. Furthermore, the vortex-like fluid flow generated along the device edge effectively prevents precipitation due to excessive lipid concentration or contact with the wall.
Hair cells in the human ear contain cilia of varying lengths that sense varied acoustic signals. Here, inspired by this, we report an artificial cilia-based sound-decoding device capable of directly recognizing and responding to sound frequencies without relying on electricity and algorithms. We create 3D-printed micrometre-sized (40–200 μm) artificial cilia-based arrays with varying length-to-diameter ratios (30–100) that can sense and decode sound frequency signals (100–6,000 Hz), including piano music and human voices, on the basis of acoustic resonance. The artificial cilia can also vibrate accordingly in water to initiate subsequent tasks such as controlling drug release profiles of two distinct therapeutics (insulin and glucagon) in an acoustic-frequency-responsive manner to treat type 1 diabetic mice. This cochlear cilia-inspired device holds potential for broad applications such as recognizing complicated physiological sounds and performing various tasks in personalized voice interactions.
危险品化学品经营许可证（带存储）