Researchers Create Self-Bending Micro-Fibers to Trap Cells

Flexible light guides developed by researchers at HUN-REN SZBK

Flexible light guides have been developed by researchers at the HUN-REN Szeged Biological Research Center. Among other things, the solution can be used to trap and move individual cells, confirms the research center.

As the article confirms in Nature Communications presenting the results of the development, optical light guides are increasingly being used in a wide range of areas, including photonic integrated circuits and photonic sensors. Similar to optical fibers, which can be bent as needed while transmitting light over long distances, the mechanical flexibility of smaller optical waveguides is critical in certain cases.

Millimeter- and centimeter-scale flexibility is essential for implantable, wearable waveguide sensors, biointerfaces, or soft robotic applications to prevent damage and ensure proper operation during operation,

confirms the research center’s website.

In addition, there are optomechanical light guide applications that rely on micrometer or nanometer scale changes in size and shape. Flexible light guide-based systems are used for ultrasonic detection, force and strain sensing, or pressure sensing. There are also flexible light guide applications with active shape control. Microactuator platforms are capable of inducing controlled shape changes in light guide structures, thereby actively modifying the performance of the device; this phenomenon is used in electro-optical switches, among other things.

Members of the HUN-REN Biophotonics and Biomicrofluidics Research Group have developed special flexible light guides that are capable of deformation by utilizing the physical pressure of the light passing through them. These microscopic structures are made of extremely soft material, so that in their curved sections, where the light pulse changes, the very small force that occurs as a result can deform the light-guiding fiber.

This method utilizes a greater pulse change than previous deformation methods based on optical tweezers, thereby exerting greater force per unit of light intensity.

The first author of the article, Gergely Iványi T., and his colleagues demonstrated the phenomenon with a semicircular light-guiding fiber 90 micrometers long and less than one micrometer thick. In the flexible light guide, light traveling along the arc exerts an outward force proportional to the curvature, causing the fiber fixed at one end to bend or, under the influence of greater light power, the originally semicircular material to straighten.

Photo: Pixabay

The optomechanical model created by the researchers was able to predict the bending of the fiber with high accuracy, which makes it possible to plan potential applications. Such applications could include moving more complex structures with light or trapping and moving individual cells based on their elasticity.

HUN-REN Researcher Awarded Grant from European Molecular Biology Organization