3D-printed micrometer-scale wireless magnetic cilia with metachronal programmability

Abstract

Biological cilia play essential roles in self-propulsion, food capture, and cell transportation by performing coordinated metachronal motions. Experimental studies to emulate the biological cilia metachronal coordination are challenging at the micrometer length scale because of current limitations in fabrication methods and materials. We report on the creation of wirelessly actuated magnetic artificial cilia with biocompatibility and metachronal programmability at the micrometer length scale. Each cilium is fabricated by direct laser printing a silk fibroin hydrogel beam affixed to a hard magnetic FePt Janus microparticle. The 3D-printed cilia show stable actuation performance, high temperature resistance, and high mechanical endurance. Programmable metachronal coordination can be achieved by programming the orientation of the identically magnetized FePt Janus microparticles, which enables the generation of versatile microfluidic patterns. Our platform offers an unprecedented solution to create bioinspired microcilia for programmable microfluidic systems, biomedical engineering, and biocompatible implants.

Magnetic nanoparticle swarm with upstream motility and peritumor blood vessel crossing ability

“…When exposed to the magnetic field, Fe 3 O 4 nanoparticles can be magnetized and form a magnetization parallel to the long axis of the shape-anisotropy particles, which is also known as the easy axis. 32,43,44 The magnetic dipole forces between nanoparticles will attract them to connect into chains and align along the magnetic field direction. When the uniform magnetic field rotates at a low frequency, particle chains tend to rotate with the magnetic field.…”

Responsive Magnetic Nanocomposites for Intelligent Shape-Morphing Microrobots

“…This technique promotes applications in intracellular sensing and fundamental mechanobiological research. The technology has been used to develop the smallest man-made jet engine and electronic blood vessels. , Complex objects can be produced using this fabrication method, such as spherical cages and helical architectures, which can be attached to polymeric chassis. , Nelson et al developed a method of printing multimaterial architectures prepared as interlocked microstructures. , Moreover, this method can directly fabricate microstructures on various substrates, such optical coherence tomography endoscopy on a fiber tip and fibroin hydrogel beam on a magnetic microparticle . With this fabrication method, it became possible to realize three-dimensional metallic and polymeric components, like spherical cages or helical architectures, which can be threaded with polymeric chassis.…”

“…153,154 Moreover, this method can directly fabricate microstructures on various substrates, such optical coherence tomography endoscopy on a fiber tip 155 and fibroin hydrogel beam on a magnetic microparticle. 156 With this fabrication method, it became possible to realize three-dimensional metallic and polymeric components, like spherical cages or helical architectures, which can be threaded with polymeric chassis. This technology was used to produce a class of vehicles and robots in the millimeter and micrometer scale.…”

3D‐Printed Artificial Cilia Arrays: A Versatile Tool for Customizable Mechanosensing

“…Previous studies have explored 3D printing magnetic cilia that exhibit coordinated metachronal motions, as well as silicone elastomer-based structures incorporating graphene resistive elements for tactile and water stimuli. [38,43] However, the concept of a fully conductive, 3D-printable high-aspect ratio cilia array sensor remains largely unexplored, as existing studies primarily focused on specific applications such as magnetic mixing and propulsion. [44] Here, we present polycaprolactone (PCL)/graphene cilia sensing arrays that combine the control and ease of fabrication of 3D printing with contact-resistance-based sensing.…”