Ring-Shaped Microparticle Autonomously Anchored in Microchannel for Intravascular Implantable Devices

This paper reports on a ring-shaped microparticle designed for implantation in medical microdevices that are autonomously anchored in microchannels simulating <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{sub-}100\ \mu \mathrm{m}$</tex> blood vessels. The particle is transported by blood flow and autonomously anchored in channels with the same diameter as the device. The ring-shaped structure is designed to reduce obstruction of blood flow. To observe how the ring-shaped structure behaves in a tube simulating blood vessels, we fabricated ring-shaped particles with a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$48 \mu \mathrm{m}$</tex> diameter and injected them into a pre-pulled glass tube with an inner diameter of approximately <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$30\ \mu \mathrm{m}$</tex> simulating a small artery. Experimental results demonstrated that the center axis of particles was aligned to the center axis of the glass tube, and the average angle between these axes was 22 degrees. These results support the feasibility of using ring-shaped microparticles for minimally invasive implantation of medical microdevices in deep-body vascular environments.