Embedding topography enables fracture guidance in soft solids

Area of Science:

• Materials Science
• Mechanical Engineering
• Biomechanics

Background:

• Natural topographical microchannels in human skin can guide propagating cracks.
• Understanding fracture mechanics in biological and synthetic materials is crucial.

Purpose of the Study:

• To investigate the guidance of fracture in elastomer membranes using topographical features.
• To explore crack control mechanisms in single and dual-layer membranes for enhanced material robustness.

Main Methods:

• Fabrication of single and dual-layer elastomer membranes with v-shaped topographical channels.
• Analysis of crack propagation and energy release in response to channel geometry and interfacial properties.
• Experimental testing to evaluate crack guidance angles and control limitations.

Main Results:

• Crack guidance in single-layer membranes is achieved by minimizing channel nadir thickness to maximize strain energy release.
• Interfacial delamination in dual-layer membranes facilitates crack guidance with lower energy requirements.
• Temporary crack guidance was observed, with non-contiguous control maintained up to 45° using multiple channels.

Conclusions:

• Topographical features in elastomer membranes can effectively guide fracture propagation.
• The study demonstrates a method for temporary crack control, applicable to flexible electronics and stretchable sensors.
• This research offers potential for improving the durability and lifespan of advanced electronic devices.