Hybrid three-dimensional printing and encapsulation process for cellulose hydrogel sensors

Area of Science:

• Materials Science
• Biomedical Engineering
• Additive Manufacturing

Background:

• Three-dimensional (3D) printing of hydrogels is crucial for wearable devices.
• Challenges exist in 3D printing hydrogels due to precursor viscosity and lack of gel phase change properties.
• Existing methods often have stringent viscosity requirements for printable hydrogels.

Purpose of the Study:

• To develop a novel hybrid 3D printing method combining direct ink writing (DIW) and vat photopolymerization (VPP).
• To broaden the adjustable mechanical properties and viscosity range of printable hydrogels.
• To improve hydrogel longevity and enable integrated printing for applications like sensors.

Main Methods:

• Introduced cellulose to modulate mechanical and rheological properties of hydrogels.
• Combined DIW and VPP for hybrid printing of hydrogels.
• Employed a dual-core coaxial printing technique for hydrogel and elastomer hybrid printing.

Main Results:

• Facilitated efficacious printing preparation of low-viscosity hydrogels, overcoming prior limitations.
• Achieved a broad spectrum of adjustable mechanical properties for hydrogels.
• Ameliorated hydrogel water loss using a hybrid printing technique and improved service life.

Conclusions:

• The novel hybrid 3D printing method expands the capabilities for creating advanced hydrogels.
• This approach enables integrated printing of encapsulation layers, enhancing hydrogel durability.
• The developed hydrogels show promise for applications in hydrogel-based sensors and wearable devices.