Project

DefeXtiles: 3D printing quasi-woven textiles via underextrusion

Overview

DefeXtiles are thin, flexible textiles of many materials that can quickly be printed into a variety of 3D forms using an inexpensive, unmodified, 3D printer with no additional software. 

This is achieved by using the material properties to encode the textile form: specifically using the periodic gaps that emerge when not enough material is being used to print. The printer moves and prints the same as it would a solid, rigid sheet, but by leveraging the stringing behavior that occurs in thermoplastic filament we can encode small gaps that afford the stretchability and flexibility. 

In a sense, the machine and the material are co-fabricating the form: 

the printer—the macroscopic form, 

the material—the microscopic form

The simplicity of this approach is what makes it so powerful. We are able to 3D print dresses for clothing design prototyping, tough badminton shuttlecocks, full-sized garments—such as a skirt—to help users “try on” clothes before ordering online, interactive lamps that turn on/off and change brightness when deformed, and a 70m roll of fabric produced in a single uninterrupted print. 

Overview

DefeXtiles are thin, flexible textiles of many materials that can quickly be printed into a variety of 3D forms using an inexpensive, unmodified, 3D printer with no additional software. 

This is achieved by using the material properties to encode the textile form: specifically using the periodic gaps that emerge when not enough material is being used to print. The printer moves and prints the same as it would a solid, rigid sheet, but by leveraging the stringing behavior that occurs in thermoplastic filament we can encode small gaps that afford the stretchability and flexibility. 

In a sense, the machine and the material are co-fabricating the form: 

the printer—the macroscopic form, 

the material—the microscopic form

The simplicity of this approach is what makes it so powerful. We are able to 3D print dresses for clothing design prototyping, tough badminton shuttlecocks, full-sized garments—such as a skirt—to help users “try on” clothes before ordering online, interactive lamps that turn on/off and change brightness when deformed, and a 70m roll of fabric produced in a single uninterrupted print. 

Motivation

For thousands of years, the manufacturing of 3D forms out of textiles has remained largely the same — fiber becomes a fabric which is then constructed into a 3D object. Knitting has made a considerable advance in changing this paradigm as the fabric and form can be generated simultaneously. Inverse design pipelines for machine knitting have further shifted the nature of textile construction towards the computational production of fully shaped textiles. Despite these advances, the ability to generate complex 3D forms with textiles outside of industrial manufacturing settings remains elusive. The high-tech approach, machine knitting, currently use expensive machines with a significant learning curve for programming. The low-tech approach, classic sewing, requires skilled and practiced hands to carry out pain-staking processes such as draping, tracing patterns onto fabric, adding seam allowances, and sewing.

As such, there is a need for a fast and accessible approach to manufacture textiles into 3D forms. 

Contributions

  • A fast and accessible approach to 3D print textiles that are much thinner and more flexible than previous methods and can also be structured in complex three-dimensional forms.
  • A study of the relevant printing parameters to control the mechanical, sensing, and aesthetic properties of the textile.
  • The development of workflows to enable control of warp direction, surface patterning, multi-material printing, and ultra-long textiles.
  • Demonstration of applications including sensing textiles, actuators, garment design/augmentation.
  • A variety of post-processing techniques that can be used on such textiles, such as heat-bonding, sewing, and de-pleating.       

Background

Fused Deposition Modeling (FDM) is the most common and inexpensive approach for 3D printing. In this technique, a material, most often a thermoplastic filament, is melted and deposited by a heated, moving printer extruder head to build up an object layer by layer. In order to yield successful prints, the speed of the nozzle head, and the amount of material extruded must be carefully coordinated to yield uniform layers. The most common parameter used to fine-tune the amount of material extruded is the extrusion multiplier (EM). 

In this work, we demonstrate that under-extrusion can be leveraged to quickly print thin, flexible, textiles. Specifically, as the extrusion multiplier decreases, there exists an ideal regime where globs form with fine strands connecting them as diagramed below.

DefeXtiles are extremely thin, less than .4 mm, meaning they can be densely packed and printed. Below we show a 70m strip of fabric produced in a single print. 

Applications

Clothing Try-On

An unnecessary cause of waste in the fashion industry is clothing ordered online that is returned due to poor fit or misrepresentation on websites. A recent study showed nearly 20-60% of clothing bought online is returned. While virtual dressing rooms are helping address this issue, the user is still unable to physically try-on and interact with the garment before shipping.  

In the second approach, full-sized pre-forms of the garments can be tried on. In this scenario, a full-sized skirt is produced in a single print. Inspired by the 4D printing approach taken by Nervous System, This was achieved by pleating then compressing the textile to fit within the XY area of the printer. The skirt was then vertically segmented and nested to fit within the height limitations of the printer. The skirt was printed at the maximum speed of 12,000 mm/min, allowing it to be printed in <30 hours. Once printed, the skirt was expanded to a size much larger than that of our print volume. It was then joined together by heat- bonding the seams, and de-pleated with a blow-dryer to expand the shape. 

Dress Design

The first is to print out miniature versions of garments that look and feel like fabric so the user can get a better sense of the form than a rigid print would allow. Additionally, the dresses can be printed around a dress form based on a scan of the customer, allowing them to physically check for proper fit. The dresses, without the dress-form, took 1-2 hours to print.

We also believe this could be useful for costume/fashion designer who renders their design digitally as a way to physically inspect and convey their ideas before moving on to physical fabrication. 

Iron-On Pocket

The ability to heat-bond DefeXtiles allows users to augment existing garments. Here, we added a PLA pocket printed with a pleat structure so it can expand to accommodate more objects, and automatically retracts when those items are removed. This allows textile augmentation similar to [22], but removes the chances of print failure due to the textile wrinkling or stretching. Additionally, this heat-bonding approach allows textiles of any size to be easily augmented.

Variations of Lace

Lace is a decorative fabric knit into complex web-like patterns. Below, we show how our approach expands the aesthetic capabilities of 3D printers to produce intricate lacelike fabrics. Here, we use different surface patterning primitives to generate lace with subtle nuances in how the pattern is encoded. 

Deformable Lampshade

In this application, we developed a lampshade to demonstrate how material textile printing allows us to incorporate capacitive sensing into a lampshade.

The user can turn the lampshade by pinching the pleats together. The light can be made brighter by pulling the pleats further apart, or dimmer by pushing them together. The ability to do both touch and proximity sensing is achieved with two-wire transmit-receive capacitive sensing.

Ultratough Shuttlecock

For synthetic shuttlecocks, the presence of gaps in the net is critical to obtaining aerodynamic properties, particularly drag coefficients, that mirror those of feathered shuttlecocks. As printing with TPU produces highly durable textiles, we were able to print tough shuttlecocks. The tail of the shuttlecock is printed as a DefeXtile to mimic feathers, and the head as a solid to mimic the rubber head. 

Tendon Based Actuator Toy

Bridging of long distances in 3D printing is possible due to the stringing behavior of melted thermoplastics. These strong bridging characteristics enable DefeXtiles to be printed mid-air, only requiring a tether point on each end. In this application, we develop a dancing person toy that can be printed in one piece with no post-processing. Both then tendons and joints are printed as DefeXtiles. The tendons are nearly fully enclosed in the print. 

Characterization

Our preliminary characterization details the flexibility and strength of our samples. In general, DefeXtiles can withstand large loads (nearly 15 kg). Additionally, DefeXtiles show improved flexibility compared to similar approaches.

Frequently Asked Questions

  1. What are some future applications of this work?
  2. How do these textiles feel?
  3. Do you use any sustainable materials to print these textiles?
  4. How expensive is the 3D printer?
  5. What is the current status of the project?
  1. What are some future applications of this work?

    In our paper, we describe many future directions, but a particularly exciting future direction is leveraging DefeXtiles to produce low-cost and effective customized surgical meshes that better reinforce organs and tissue after surgery. 3D printed surgical implants have already been studied with promising results. Additionally, If loaded with antibiotics, such as ciprofloxacin HCl, the degradation would slowly release the antibiotic preventing infection. Another feature is that the mechanical properties of the mesh could be tuned to match that of the tissue being supported. 

  2. How do these textiles feel?

    The textiles feel very similar to a tulle or mesh material with a soft and flexible feel. When shown many people cannot believe the textiles came from a 3D printer! 

  3. Do you use any sustainable materials to print these textiles?

    Largely throughout the paper, we use poly-lactic acid (PLA). This is a biodegradable plastic that often comes from corn starch; however, biodegradation only occurs in an industrial composting setting so the level of sustainability is limited. One route we are exploring in the future is using algae and coffee ground doped PLA, as a more sustainable alternative. Another option is that these textiles can be remelted, mixed with some fresh material, and extruded into a new filament (these at-home machines are expensive, but are getting cheaper) - also off-the-shelf filaments made from recycled materials do exist. 

  4. How expensive is the 3D printer?

    This approach uses an FDM printer. These printers have become extremely cheap, starting at ~$250. These printers are also widely available in most maker spaces. 

  5. What is the current status of the project?

    This project is relatively mature and is being present at UIST 2020 on October 23rd. With the base technology mostly established, reach out to me if you want to collaborate!

 Acknowledgments 

The authors would like to thank Neil Gershenfeld, Ken Nakagaki, Lining Yao, Stefanie Mueller, Anya Quenon, Hila Mor, Joao Wilbert, Lea Albaugh, Joanne Leong for the fruitful discussions. Thanks to Paula Aguilera and Jonathan Williams for their help with filming. Additionally, the authors are grateful to Marian and Roger Forman, the first author’s parents, for allowing their basement to become a Fab Lab during the COVID-19 pandemic.