# Novel High‐Efficient Method to Generate Fragmented Nano‐ and Microfibers Enabling an Additive for Bio‐Inks

## TL;DR

This paper introduces a new UV-based method to create fragmented fibers for use in bio-inks, improving tissue printing by enhancing structure and cell survival.

## Contribution

A novel UV irradiation technique for controlled fiber fragmentation, offering a scalable and accessible alternative to current methods.

## Key findings

- UV irradiation effectively breaks electrospun fibers into controlled lengths.
- The method is validated on PCL and gelatin blends, showing biocompatibility and cost-effectiveness.

## Abstract

As an emerging technology, biofabrication combines biopolymers and living cells to create functional tissues, allowing the development of structures that closely mimic native tissues. The use of fiber‐reinforced materials is of particular interest, as it enhances both mechanical properties and cellular behavior. Incorporating fiber fragments into bio‐inks not only strengthens printed structures but also supports cell survival by lowering polymer concentrations and thus the stress exerted on the cells during printing. A key factor in optimizing fiber‐reinforced bio‐inks is the controlled fiber shortening, comprising cutting or breaking, which improves printability and mechanical integrity of printed constructs. However, current methods for fiber fragmentation face significant limitations, including material‐specific dependencies, scalability challenges, and requirements of specialized equipment, which may not be accessible in all laboratories. To overcome these challenges, we introduce a novel approach utilizing ultraviolet irradiation to achieve controlled fiber fragmentation. The average fiber length resulting from specific irradiation times can be estimated using a multi‐modal Weibull analysis. This technique is validated on fibers made of polycaprolactone (PCL) and gelatin blends, demonstrating its cost‐effectiveness, biocompatibility, and simplicity. This study provides a practical solution for fiber fragment production and average length estimation, offering an accessible and scalable alternative for fiber‐based biofabrication applications.

Electrospun fibers are randomly spun on a substrate. Subsequent UV irradiation results in a deliberate breakage of the fibers. The collection of the fragments enables a simple way to make tailor‐made additives for bio‐inks. Dependent on the duration of irradiation, the fiber fragment length distribution changes. The cumulative fiber length distribution is analyzed, yielding fundamental equations for application.