Quantitative Investigation into the Design and Process Parametric Effects on the Fiber‐Entrapped Residual Charge for a Polymer Melt Electrohydrodynamic Printing Process

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

doi:10.1002/mame.202100766

Cited by 10 publications

(16 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, the discharge process is weakened due to the increasing height of scaffolds and the enlarging gap between the fibers from different layers. [28] Thus, with an increment in layer number, more positive charges are accumulated at the intersection point, as shown in Figure 4b. Third, the inflight jet and the deposited scaffold (or fibers) are polarized due to the existence of a high electric field.…”

Section: Deviation Occurs In Fibers Separated By a Small Inter-fiber ...mentioning

confidence: 90%

“…As stated earlier, with the increase in the build-up height of the scaffolds and the increase of gap area in the vertical direction within the scaffolds, more positive charges are accumulated. [28] For the 0-90 pattern with a large-small sequence (Figure 5b), the height of point H, the local highest point, for the targeted intersection point is larger compared with that of the small-large sequence (Figure 5a). However, the gaps between the topmost fibers and the preceding fibers or between the topmost fibers and the collector plate, as delineated by the blue lines, exhibit similar morphology between these two scenarios.…”

Section: -90 Pattern Versus 0-𝜽 Patternmentioning

confidence: 93%

“…First, the inflight jet (Region J in Figure 4a) is positively charged due to the field-induced emission and charge in-jection mechanism. [23,28] Second, the charges entrapped in deposited scaffolds are difficult to be completely dissipated because of the poor conductivity of the possessed polymer. Moreover, the discharge process is weakened due to the increasing height of scaffolds and the enlarging gap between the fibers from different layers.…”

Section: Deviation Occurs In Fibers Separated By a Small Inter-fiber ...mentioning

confidence: 99%

See 2 more Smart Citations

Effects of Printing Sequence on the Printing Accuracy of Melt Electrowriting Scaffolds

Zhang

Cao

Zaeri

et al. 2022

Macro Materials & Eng

Self Cite

View full text Add to dashboard Cite

Melt electrowriting (MEW), an emergent additive manufacturing process, shows significant potential in fabricating high‐fidelity fibrous scaffolds for tissue engineering applications. However, fiber deviation can deteriorate the printing accuracy of MEW. To evaluate the printing accuracy, an evaluation protocol along with an index (Ip) is proposed. For the first time, 0–90 patterned and 0–θ patterned scaffolds with varying inter‐fiber distances along different printing directions are fabricated to establish the dependence of Ip on two distinct printing sequences. One sequence is the small–large sequence, which first prints the fibers separated by a small inter‐fiber distance, followed by fibers separated by a large inter‐fiber distance. Alternatively, for the large–small sequence, the fibers separated by a large inter‐fiber distance are printed prior to the fibers separated by a small inter‐fiber distance. The small–large sequence contributes to larger Ip results compared to the large–small sequence. Moreover, the printing sequence has more significant effects on the Ip for the 0–θ pattern compared to the 0–90 pattern. These differences can be attributed to different fiber morphologies at the intersection points, accompanied by resultantly varying charge amounts, which gives an insight into the cause of fiber deviation phenomena.

show abstract

Section: Deviation Occurs In Fibers Separated By a Small Inter-fiber ...mentioning

confidence: 90%

Section: -90 Pattern Versus 0-𝜽 Patternmentioning

confidence: 93%

Section: Deviation Occurs In Fibers Separated By a Small Inter-fiber ...mentioning

confidence: 99%

See 1 more Smart Citation

Effects of Printing Sequence on the Printing Accuracy of Melt Electrowriting Scaffolds

Zhang

Cao

Zaeri

et al. 2022

Macro Materials & Eng

Self Cite

View full text Add to dashboard Cite

show abstract

“…In a previous study, the residual charge amount in MEW-enabled scaffold was successfully measured using a nanocoulomb meter[ 30 ]. While investigating the effect of different design and process parameters on the residual charge amount, the effect of fiber morphologies on the residual charge amount is noteworthy.…”

Section: Introductionmentioning

confidence: 99%

“…While investigating the effect of different design and process parameters on the residual charge amount, the effect of fiber morphologies on the residual charge amount is noteworthy. The residual charges entrapped within a fibrous wall composed of discretely deposited fibers are usually more than those in a fibrous wall composed of compactly deposited fibers[ 30 ], in which “fiber sagging”[ 31 ] occurs, and as a result, contact discharge happens more easily. The effects of different process parameters on the residual charge amount can be either dependent or independent of fiber morphologies (MDE and MIE).…”

Section: Introductionmentioning

confidence: 99%

A holistic model for melt electrowritten threedimensional structured materials based on residual charge

Cao¹,

Zhang²,

Zaeri³

et al. 2022

IJB

View full text Add to dashboard Cite

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 characteristic curve and characteristic surface are advanced to analyze the complex interplay between fiber morphologies and residual charge. Different parameters contribute to this interplay either by affecting residual charge, fiber morphologies, or the three charge effects. To validate this model, the effects of lateral location and grid number (i.e., number of fibers printed in each direction) on the fiber morphologies are investigated. Moreover, the “fiber bridging” phenomenon in parallel fiber printing is successfully explained. These results help to comprehensively understand the complex interplay between the fiber morphologies and the residual charge, thus furnishing a systematic workflow to improve printing accuracy.

show abstract

Gradient Biomolecular Immobilization of 3D Structured Poly‐ɛ‐caprolactone Biomaterials toward Functional Engineered Tissue

Zaeri,

Zgeib,

Zhang

et al. 2023

Macro Materials & Eng

Self Cite

View full text Add to dashboard Cite

Additive manufacturing (AM) enables the tailored production of precision fibrous scaffolds toward various engineered tissue models. Moreover, by functionalizing scaffolds in either a uniform or gradient pattern of biomolecules, different target tissues can be fabricated in vitro to capture key characteristics of in vivo cellular microenvironments. However, current engineered tissue models lack the appropriate cellular cues that are needed to deterministically direct cell behavior. Specifically, tunable and reproducible scaffold‐guided stimuli are identified herein as the missing link between biomaterial structure and cellular behavior. Therefore, the bottleneck of precision control is addressed here over the immobilization of patterned biomolecular stimuli with either uniform or gradient distribution over the AM‐enabled 3D biomaterial model as a function of different growth factors exposure variables, protocols, and various scaffold architectural design parameters. The produced study outcomes herein will improve the directing and guiding of biological cell attachment and growth direction in the context of scaffold‐guided stimuli techniques. Therefore, unprecedented control is presented here over 3D structured biomaterial gradient functionalization and immobilization of biomolecules toward biomimetic tissue architectures.

show abstract

Quantitative Investigation into the Design and Process Parametric Effects on the Fiber‐Entrapped Residual Charge for a Polymer Melt Electrohydrodynamic Printing Process

Cited by 10 publications

References 26 publications

Effects of Printing Sequence on the Printing Accuracy of Melt Electrowriting Scaffolds

Effects of Printing Sequence on the Printing Accuracy of Melt Electrowriting Scaffolds

A holistic model for melt electrowritten threedimensional structured materials based on residual charge

Gradient Biomolecular Immobilization of 3D Structured Poly‐ɛ‐caprolactone Biomaterials toward Functional Engineered Tissue

Contact Info

Product

Resources

About