Page 95 - IJB-9-2

International Journal of Bioprinting

RESEARCH ARTICLE
A holistic model for melt electrowritten three-

dimensional structured materials based on
residual charge

Kai Cao, Fucheng Zhang, Ahmadreza Zaeri, Ralf Zgeib, Robert C. Chang*

Department of Mechanical Engineering, Stevens Institute of Technology, Hoboken, New Jersey
07030, USA
(This article belongs to the Special Issue: Near-field Electrospinning and Melt Electrowriting for
Biotechnology and Biomedicine)

Abstract

The printing accuracy of polymer melt electrowriting is adversely affected by the
residual charge entrapped within the fibers, especially for three-dimensional (3D)
structured materials or multilayered scaffolds with small interfiber distances. To
clarify this effect, an analytical charge-based model is proposed herein. The electric
potential energy of the jet segment is calculated considering the amount and
distribution of the residual charge in the jet segment and the deposited fibers. As
the jet deposition proceeds, the energy surface assumes different patterns, which
constitute different modes of evolution. The manner in which the various identified
parameters affect the mode of evolution are represented by three charge effects,
including the global, local, and polarization effect. Based on these representations,
typical modes of energy surface evolution are identified. Moreover, the lateral
*Corresponding author:
Robert C. Chang characteristic curve and characteristic surface are advanced to analyze the complex
(rchang6@stevens.edu) interplay between fiber morphologies and residual charge. Different parameters
contribute to this interplay either by affecting residual charge, fiber morphologies, or
Citation: Cao K, Zhang F, Zaeri A,
et al., 2023, A holistic model for melt the three charge effects. To validate this model, the effects of lateral location and grid
electrowritten three-dimensional number (i.e., number of fibers printed in each direction) on the fiber morphologies
structured materials based on residual are investigated. Moreover, the “fiber bridging” phenomenon in parallel fiber printing
charge. Int J Bioprint, 9(2): 656.
https://doi.org/10.18063/ijb.v9i2.656 is successfully explained. These results help to comprehensively understand the
complex interplay between the fiber morphologies and the residual charge, thus
Received: July 20, 2022
furnishing a systematic workflow to improve printing accuracy.
Accepted: September 29, 2022
Published Online: December 28, Keywords: Residual charge; Energy analysis; Charge polarization; Fiber morphologies;
2022
Melt electrohydrodynamic printing
Copyright: © 2022 Author(s).
This is an Open Access article
distributed under the terms of the
Creative Commons Attribution
License, permitting distribution, 1. Introduction
and reproduction in any medium,
provided the original work is Engineered tissue strategies aim to produce three-dimensional (3D) physiologically
properly cited. relevant tissue constructs, which include three essential components, namely, living
[1]
Publisher’s Note: Whioce cells, biomolecules, and biomaterial . To achieve this, the living cells can either be
Publishing remains neutral with directly printed as a component of the bioink (termed direct bioprinting strategy, e.g.,
regard to jurisdictional claims in [2] [3] [4]
published maps and institutional material jetting-based , extrusion-based , and vat polymerization-based bioprinting )
affiliations. or be seeded onto the functionalized material scaffold fabricated in advance (termed

Volume 9 Issue 2 (2022) 87 https://doi.org/10.18063/ijb.v9i2.656