---
title: "LLNL pioneering 3D printing of color-changing CLCEs"
url: https://www.voxelmatters.com/llnl-pioneering-3d-printing-of-color-changing-clces/
date: 2025-04-01
modified: 2025-04-01
lang: en
author: "Tess Boissonneault"
description: "A team of researchers from the Lawrence Livermore National Laboratory (LLNL), Harvard University and the University of Pennsylvania are pioneering a method for 3D printing cholesteric liquid crystal elastomers (CLCEs)...."
categories:
  - "Advanced Polymers"
  - "AM Research"
  - "Materials"
tags:
  - "future"
image: https://www.voxelmatters.com/wp-content/uploads/2025/03/llnl-research-2-640x324.jpg
word_count: 407
---

# LLNL pioneering 3D printing of color-changing CLCEs

A team of researchers from the [Lawrence Livermore National Laboratory (LLNL)](https://www.voxelmatters.com/llnl-researchers-harness-3d-printing-for-fusion-energy/), Harvard University and the University of Pennsylvania are pioneering a method for 3D printing cholesteric liquid crystal elastomers (CLCEs). These innovative materials, which have unique color-changing properties, are being investigated for myriad applications, including smart textiles, soft robotics and more.

CLCEs are characterized as mechanochromic materials, meaning that they change color based on external stimuli like stresses or deformation. These dynamic properties are combined with a rubber-like texture, which makes CLCEs very versatile. Up until very recently, however, the main method for producing CLCE components was direct ink writing (DIW). While suitable for producing CLCE films, this production method is not able to create three dimensional structures.

[![LLNL CLCE Coaxial Direct Ink Writing](https://www.voxelmatters.com/wp-content/uploads/2025/03/research-llnl-1.jpg)](https://www.voxelmatters.com/wp-content/uploads/2025/03/research-llnl-1.jpg)Coaxial 3D printing of silicone-supported CLCE filament (Advanced Materials)

The cooperative research team therefore set out to 3D print CLCEs using coaxial direct ink writing. This technique utilizes two materials to create 3D structures: a low-viscosity cholesteric liquid crystal ink (used as the core material) and a transparent, yield-stress silicone ink (used as the shell to contain the CLCE). As the research team writes in a [recently published study](https://advanced.onlinelibrary.wiley.com/doi/10.1002/adma.202416621):

"While CLCEs are printed via direct ink writing (DIW) to fabricate free-standing films, complex 3D structures are not fabricated due to the opposing rheological properties necessary for cholesteric alignment and multilayer stacking. Here, 3D CLCE structures are realized by utilizing coaxial DIW to print a CLC ink within a silicone ink. By tailoring the ink compositions, and thus, the rheological properties, the cholesteric phase rapidly forms without an annealing step, while the silicone shell provides encapsulation and support to the CLCE core, allowing for layer-by-layer printing of self-supported 3D structures."

In the study, the researchers 3D printed a series of bistable domes that, when compressed, displayed color changes. The 3D printed domes also have shape memory properties, snapping nap to their original state when inverted. As the technique is further developed, the LLNL team and its partners believe that coaxial DIW could be used to produce color-changing 3D structures with mechanochromic inks, which could be used in soft robotics, smart wearables and other applications like cryptography.

Additive manufacturing has been of interest at the LLNL in recent years, with researchers there working on a number of cutting edge projects, including using [multi-material 3D printing for cellular microfluidics](https://www.voxelmatters.com/llnl-advances-cellular-fluidics-with-multi-material-3d-printing/), improving the [optical absorptivity of metal AM](https://www.voxelmatters.com/llnl-enhances-absorptivity-of-metal-3d-printing-powders/) powders using nanoscale features and leveraging [AM technology to advance fusion energy](https://www.voxelmatters.com/llnl-researchers-harness-3d-printing-for-fusion-energy/).