Supersoft lithography: candy-based fabrication of soft silicone microstructures

Area of Science:

• Biomaterials Engineering
• Tissue Engineering
• Microfabrication

Background:

• Replicating physiologically soft microstructures is challenging for applications like cell culture.
• Existing methods may not be suitable for creating complex features in low-modulus materials.

Purpose of the Study:

• To develop an accessible fabrication technique for microstructured soft silicone materials (E < 1 kPa).
• To adapt confectionery 'hard candy' recipes for use as dissolvable templates in silicone replica molding.
• To demonstrate the utility of these soft microstructures in measuring cellular forces.

Main Methods:

• Modified sugar-based candy recipes were used as sacrificial templates.
• Silicone replica molding was performed using these candy templates.
• Templates were dissolved in water to release the microstructured silicone.

Main Results:

• Successfully fabricated microstructures in soft silicone materials (Young's modulus < 1 kPa).
• Demonstrated easy removal of candy templates by dissolution.
• Utilized the soft microstructures to measure forces generated by fibroblast-laden contractile tissues.

Conclusions:

• The developed technique offers a simple and effective way to replicate microstructures in soft silicones.
• This method is highly promising for creating physiologically relevant microenvironments for cell culture.
• The application in force measurement highlights the potential for studying cell-tissue mechanics.