The Conformal Design of an Island-Bridge Structure on a Non-Developable Surface for Stretchable Electronics

Area of Science:

• Materials Science
• Mechanical Engineering
• Surface Physics

Background:

• Conformal transfer of inorganic stretchable electronics to non-developable surfaces is challenging.
• Existing epidermal electronics designs are optimized for soft surfaces, lacking constraints for hard surfaces.

Purpose of the Study:

• To address the conformal design of island-bridge structures on hard, non-developable surfaces.
• To establish design rules for high-performance inorganic stretchable electronics on complex geometries.

Main Methods:

• Developed a conformal model for island structures on torus surfaces to relate island size to surface curvature.
• Utilized energy minimization and material failure limits to determine critical island width.
• Employed finite element analysis (FEA) to study bridge stiffness dependency on geometric parameters.
• Applied geometric mapping to determine location-dependent stretchability requirements for bridges.

Main Results:

• Established a critical non-dimensional width for island conformability based on thickness, adhesion energy, and surface principal curvatures.
• Provided insights into the tensile stiffness of bridges as a function of geometric parameters.
• Defined location-dependent stretchability demands for bridges on non-developable surfaces.

Conclusions:

• This study offers a design framework for achieving full conformability of stretchable electronics on hard, non-developable surfaces.
• The findings are crucial for advancing applications requiring robust electronic integration with complex geometries.