Digital-to-physical process for graded nonwoven microfiber networks using MEW-VTP

Overview

This solution offers a digital-to-physical manufacturing approach that translates a target 3D property map into a microfiber nonwoven network with engineered porosity and stiffness gradients. By combining melt electrowriting (MEW) with viscous thread printing (VTP), the platform produces continuous 3D porosity gradients in textile and foam-like structures at the microscale. An autonomous data-collection and modeling workflow, driven by Gaussian-process active learning, replaces manual trial-and-error prototyping with a reproducible route from digital specification to physical coupon. The result is a faster, more predictable way to prototype and test graded nonwoven structures for applications requiring spatially tuned mechanical response and pore architecture.

Technical specifications

Key features:

• MEW-VTP process extends viscous thread printing to micron-scale fibers, enabling fine control over pore structure and mechanical properties
• 3D property map input allows users to specify desired stiffness and porosity gradients in X, Y, and Z directions
• Autonomous fabrication and testing campaign of approximately 300 coupons, each micro-CT scanned and compression tested
• Gaussian-process active learning maps process inputs (voltage, temperature, V*, H*, line spacing, layer spacing) to pore-volume distributions and stress-strain response
• Inverse design capability that generates statistically equivalent fiber networks from a target property map, rather than reproducing every fiber coordinate
• Micro-CT validation targeting no more than 5% deviation between designed and realized global and spatial pore distributions
• Tiled MEW-VTP heads providing a scale-up pathway to larger sheets and multilayer prototypes
• Validated materials including thermoplastic polyurethane (TPU) processing ranges

Technology readiness level

The platform builds on demonstrated Gaussian-process prediction of layer height, modulus, and full stress-strain response, along with prior spatial control of stiffness and porosity in VTP structures. Preliminary MEW-VTP behavior has been observed in prior Army-supported work. The current program focuses on commissioning the MEW-VTP platform, establishing stable TPU processing windows, and validating micro-CT segmentation and compression testing. An autonomous campaign of roughly 300 specimens will populate the process-property model, followed by inverse design and fabrication of a 15 x 15 x 5 mm graded specimen. Final validation will demonstrate pore-volume-distribution agreement within 5%, document mechanical performance, and define a tiled scale-up route. The technology is currently at an early-to-mid development stage, transitioning from laboratory demonstration toward reproducible prototyping.