Abstract
Small-scale cilia-like devices that can manipulate fluids in narrow spaces have great potential in microfluidics, biomechanics, biomedical engineering, and other applications. However, prior studies mostly focus on artificial cilia for pumping fluids in lab-on-a-chip microfluidic applications. The design and control of artificial cilia for transporting viscous mucus in confined and tubular structures remain challenging and medical devices such as airway stents with ciliary function are still missing. Herein, a method is reported that enables integrating artificial cilia arrays on 3D curved surfaces and an airway ciliary stent is presented for excessive mucus transportation. The method allows encoding bioinspired non-reciprocal motion and metachronal waves for efficient fluid pumping in tubular structures. The method also introduces a lubricant hydrogel coating layer on artificial cilia inspired by the periciliary layer in airway cilia, which further enhances viscous fluid transportation. It is demonstrated that a novel ciliary airway stent can transport viscous porcine mucus in a lung phantom even faster than the respiratory cilia in a healthy human lung. The methods of designing, integrating, and controlling artificial cilia on 3D curved surfaces thus enable the unprecedented function of removing excessive mucus beyond traditional airway stents for treating various lung diseases in a minimally invasive manner.