3D Magnetic Voxel Assembly for Programmable Shape-Morphing Machines

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Solution Overview

Problem

Existing methods for fabricating small-scale magnetic soft machines are limited by the inability to integrate arbitrary material compositions and geometries, and suffer from constraints such as extrusion-based approaches failing to produce finer magnetic fibers and lithography-based methods restricting magnetization programming.

Innovation Solution

A bottom-up assembly method involving heterogeneous voxels with predefined shape, size, and magnetic properties, bonded using a bonding agent, allowing for the fabrication of deformable magnetic machines with arbitrary 3D geometries and magnetization profiles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If extrusion-based 3D printing methods are used to fabricate magnetic soft machines, then complex 3D structures with arbitrary geometries can be created, but the method cannot fabricate finer magnetic soft fibers due to demanding storage modulus requirements and extrudate swell

Engineering Contradiction:
Improvecomplex 3D structuresVSAvoidfiber fineness
Core Design Contradiction:
ShapeVSManufacturing precision

Solution Approach 1:

The patent divides the magnetic soft machine into discrete magnetic voxels (small cubic units) that can be independently fabricated and then assembled. This segmentation allows each voxel to be precisely controlled during fabrication while the overall structure achieves complex 3D geometries. The voxel-based approach eliminates the extrusion limitations by using a different fabrication strategy for each small unit.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from continuous extrusion-based fabrication to a discrete voxel assembly approach, effectively moving from a continuous manufacturing paradigm to a modular assembly paradigm. This dimensional change in the fabrication strategy allows bypassing the extrudate swell problem by not using extrusion at all, instead using direct digital fabrication or assembly of pre-fabricated voxels.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If magnetic particles are added to soft elastomers for extrusion-based fabrication, then magnetic actuation capability is achieved, but performance deteriorates due to storage modulus requirements

Engineering Contradiction:
Improvemagnetic actuation capabilityVSAvoidstorage modulus
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The patent applies magnetic particles only to specific voxels that require magnetic actuation, rather than uniformly distributing them throughout the entire structure. This local quality approach allows magnetic functionality to be placed precisely where needed while maintaining optimal mechanical properties in other regions. Different voxels can have different magnetic particle concentrations or none at all, depending on their functional requirements.

Inventive Principle:
Principle #3Local quality

3Manufacturing precision

If UV lithography-based 3D printing methods are used to program magnetization, then arbitrary magnetization profiles can be achieved, but strong local interaction of magnetic particles in uncured liquid photoresists restricts programming of neighboring voxels

Engineering Contradiction:
Improvemagnetization programming precisionVSAvoidvoxel independence
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent performs magnetization programming after the voxels are assembled into the final structure, rather than attempting to program magnetization during the fabrication process. This preliminary action (assembling first, then magnetizing) eliminates the interference from uncured photoresist and allows each voxel to be independently magnetized without restriction from neighboring voxels. The magnetic field can be applied uniformly or selectively to achieve precise magnetization profiles.

Inventive Principle:
Principle #10Preliminary action

4Ease of manufacture

If top-down fabrication approaches are used, then manufacturing process is simplified, but accuracy of formation of magnetic machines is limited

Engineering Contradiction:
Improvefabrication process simplicityVSAvoidmachine formation accuracy
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent uses a bottom-up assembly approach where precise magnetic voxels are fabricated individually or in small groups and then assembled into the final complex structure. This segmentation allows high precision in fabricating each voxel component while maintaining relative simplicity in the overall assembly process. The modular nature enables parallel fabrication and simplifies quality control compared to attempting to fabricate the entire complex structure in a single top-down process.

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables the production of complex 3D magnetic soft machines with high resolution, enabling programmable shape-morphing and diverse biomedical functions, such as peristaltic pumping and cargo transport, by decoupling material, geometry, and magnetization profiles.

Implementation Method 1

The external magnetic field has emerged as a promising stimulus choice for safe, fast, precise, dexterous, and wireless actuation of soft machines

Methodology Applied
Scientific EffectMagnetic field actuation: Magnetoelastic Effects

Implementation Method 2

bonding the plurality of voxels one to another using a bonding agent in accordance with the produced blueprint to assemble the magnetic machine

Methodology Applied
Scientific EffectBonding: Adhesive

Data Source

PatentEP3954531B1Method of fabricating a magnetic deformable machine and deformable 3D magnetic machine
Publication Date: 2025.07.02 MAX PLANCK GESELLSCHAFT ZUR FOERDERUNG DER WISSENSCHAFTEN EV
  • EP3954531B1 patent drawingFigure 1a~1e
  • EP3954531B1 patent drawingFigure 2a~2d
  • EP3954531B1 patent drawingFigure 3a~3d

AI summary

The present invention relates to a method of fabricating magnetic deformable machines comprising heterogeneous voxels, as well as to a deformable 3D magnetic machine, the magnetic machine having a size of less than 10000 mm, the magnetic machine comprising a plurality of voxels of which at least one, preferably some, are magnetic, with at least one of the voxels having a Young's modulus of less than 500 MPa, the plurality of voxels being bonded one to another with a bonding agent, wherein each voxel is of predefined shape, size, has predefined magnetic properties and predefined material properties.