Reviewed by Lexie CornerApr 29 2025
Researchers at Tsinghua University have published a study proposing an enhanced Digital Light Processing (DLP) 3D printing method capable of creating composite magnetic structures using multiple materials in a single step.
(a) Schematic of the multi-material one-step printing process, demonstrating the sequential switching of three different resin tanks during printing to achieve composite structures in a single step. (b) Illustration of the curing process of resin containing magnetic particles under UV light. (c) SEM image of the cross-section of a printed sample, indicating uniform layer height and stable printing. (d) EDS image of the printed sample, depicting the elemental distribution across the sample's cross-section. Image Credit: Jiadao Wang, State Key Laboratory of Tribology in Advanced Equipment, Department of Mechanical Engineering, Tsinghua University.
A soft robot composed of a combination of hard magnetic and superparamagnetic materials was also developed.
The current study presents a soft robot based on DLP 3D printing technology, which shows significant potential for the design and production of multifunctional soft robots.
Various methods are available for fabricating 2D or 3D magnetic structures. However, traditional processes like mold-assisted forming and UV lithography are restricted by mold shapes and material types, posing challenges in fabricating complex magnetic structures.
Jiadao Wang, Professor, Tsinghua University
Wang added, “These methods demand uniform composition throughout the structure, complicating the creation of multifunctional magnetic structures with multiple materials. While multi-step assembly and material bonding techniques can combine different materials for various applications, they struggle with ensuring the size range and precision of the fabricated structures.”
Wang, the study’s author, suggested using an enhanced DLP approach in response to these issues. This technique enables the creation of composite magnetic structures made from multiple materials in a single printing process. The team used this method to create a variety of composite structures, including gradient composites with varying magnetic material concentrations, hard magnetic-superparamagnetic composites, and magnetic soft-hard material composites.
Wang noted that the study introduces new features and concepts for multi-material, one-step 3D printing of magnetically driven soft structures. The study includes mechanical and magnetic characterization of 3D printed structures and presents sample applications.
The design and verification of a soft robot composed of hard magnetic and superparamagnetic materials are discussed in detail, with emphasis on the distribution of magnetic domains and the thermal effects of the superparamagnetic material.
The study evaluates the ground maneuverability of these soft robots, demonstrating their ability to overcome obstacles while capturing and transporting items. Additionally, the robots' swimming capabilities in a liquid environment were tested, and their swimming posture was analyzed using a multiphysics coupled simulation.
According to the author, this research could be valuable for designing capsule robots with drug delivery capabilities, enabling them to transport drug particles to wound sites in biological tissues. Challenges such as the adhesion of high-concentration magnetic structures to release films, reduced effective curing depth, sedimentation of magnetic particles, and biocompatibility issues would need to be addressed.
The study's authors include Zhaoxin Li, Ding Weng, Lei Chen, Yuan Ma, Zili Wang, and Jiadao Wang.
This study was funded by the National Natural Science Foundation of China (NSFC) under Grant No. 52275200 and Grant No. 52205312.
Journal Reference:
Li, Z. et al. (2025) Enhanced Digital Light Processing-Based One-Step 3-Dimensional Printing of Multifunctional Magnetic Soft Robot. Cyborg and Bionic Systems. doi.org/10.34133/cbsystems.0215