---
title: "Researchers develop degradable 4D printed actuators using PETG and PVA"
url: https://www.voxelmatters.com/researchers-develop-degradable-4d-printed-actuators-using-petg-and-pva/
date: 2026-02-10
modified: 2026-02-10
lang: en
author: "Joseph Caron-Dawe"
description: "A team of researchers from the Universidad Politécnica de Madrid and IMDEA Materials Institute has developed a method for creating shape-changing devices through controlled material degradation, which opens up the..."
categories:
  - "AM Research"
  - "Medical AM"
  - "Medical Research"
  - "Orthopedic Implants"
  - "Research & Education"
tags:
  - "future"
image: https://www.voxelmatters.com/wp-content/uploads/2026/02/IMDEA-01-640x400.jpeg
word_count: 329
---

# Researchers develop degradable 4D printed actuators using PETG and PVA

A team of researchers from the Universidad Politécnica de Madrid and [IMDEA Materials Institute](https://www.voxelmatters.com/imdea-develops-new-3d-printable-high-entropy-superalloy/) has developed a method for creating shape-changing devices through controlled material degradation, which opens up the possibilities for adaptive medical implants and soft robotics applications.

By combining [polyethylene terephthalate glycol-modified (PETG) with polyvinyl alcohol (PVA)](https://www.voxelmatters.com/voxelmatters-composites-am-focus-2026/) in multi-material 4D printing, actuators that transform their geometry when exposed to water were created.

[Published in Additive Manufacturing](https://www.sciencedirect.com/science/article/pii/S2214860425004397#sec0065), the study explored the mechanical, biological, and degradation properties of both polymers to assess their viability for suitable engineering applications.

The researchers manufactured test specimens using fused filament fabrication technology with a Bambu Lab X1 Carbon printer. The PVA samples showed significant property changes during water immersion, with elastic modulus, yield strength, and tensile strength decreasing by an approximate average of 30% after 80 minutes of submersion. The material transitioned from brittle to ductile behavior as degradation progressed.

![Researchers develop degradable 4D-printed actuators using PETG and PVA](https://www.voxelmatters.com/wp-content/uploads/2026/02/IMDEA-02-216x340.jpg)

Degradation rates correlated with exposed surface area-to-volume ratios rather than infill patterns during the study. Those specimens which had a higher surface area degraded faster, following exponential decay curves that allowed researchers to predict temporal behavior. The team used Python to develop computer vision algorithms that tracked the degradation progression, through sequential imaging.

PETG demonstrated superior elastic energy storage capacity, although water exposure accelerated stress relaxation. The polymer maintained structural integrity under immersion while exhibiting viscoelastic behavior that researchers quantified using Prony series equations.

The researchers designed a shock absorber-inspired device combining a PETG helical spring with a PVA serpentine spring. As the PVA component degraded in water, it progressively released mechanical constraints on the compressed PETG spring, enabling controlled shape transformation over 222 minutes.

Cytocompatibility tests using human mesenchymal stromal cells showed both materials supported cell viability exceeding 89% after six days, with the study concluding this promotes their use in biomedical applications . PVA structures dissolved within 24 hours without harmful effects, while PETG maintained biocompatibility throughout the testing period. Further suggested potential applications by the researchers included bone distraction devices.