Conductive Microserpentine U-Bends for Strain-Tolerant Biosensors
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Solution Overview
Problem
Existing stretchable electronics using inorganic materials like silicon and aluminum face electrical failure due to mechanical deformation at small tensile strains, and there is a lack of understanding of 3D printed geometries for dynamic microelectrodes in stretchable and flexible devices.
Innovation Solution
Development of microserpentines with specific u-bend configurations and compositions, coated with conductive materials, integrated into flexible substrates with insulating layers, using additive manufacturing to create durable and conductive microelectrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If inorganic materials like silicon and aluminum are used in stretchable electronics, then electrical conductivity is maintained, but mechanical flexibility and strain tolerance deteriorate due to electrical failure at small tensile strains
Solution Approach 1:
The microserpentine structure segments the conductive path into multiple u-bend sections, allowing each segment to deform independently during stretching. This segmentation enables the overall structure to accommodate large strains while maintaining continuous electrical conductivity through the distributed network of conductive elements.
Solution Approach 2:
The microserpentine employs curved u-bend geometries instead of straight conductive paths. The curved configuration allows the conductor to flex and deform elastically under tensile strain, distributing mechanical stress away from critical failure points while maintaining electrical continuity. The specific α angle optimization enhances this curvature effect to maximize stretchability.
2Reliability
If standard serpentine designs are used in flexible electronics, then strain performance is enhanced, but understanding of 3D printed geometries and their application to dynamic microelectrodes is missing
Solution Approach 1:
The invention systematically varies geometric parameters including the u-bend completeness angle (α), the number of bends, and the overall serpentine configuration to optimize stretchability. By establishing quantitative relationships between these parameters and strain performance, the invention provides a framework for designing 3D printed microelectrodes with tailored mechanical and electrical properties for dynamic applications.
3Adaptability or versatility
If microserpentines with higher α values are used, then stretchability increases, but conductivity may deteriorate due to increased path length and potential coating discontinuities
Solution Approach 1:
The microserpentine employs a composite structure combining a flexible polymer or metal core with a conformal conductive coating layer. This composite design allows the core to provide mechanical flexibility and stretchability while the coating ensures electrical conductivity. The conformal nature of the coating adheres tightly to the core geometry, preventing discontinuities even at high α values that maximize stretchability.
Data Source
AI summary
Various embodiments relate to a microserpentine including a plurality of u-bends, each having a degree of completeness (α), in which an α value of 0° corresponds to a semi-circular shape, and in which an α value of +90° corresponds to a complete circle and −90° corresponds to a straight shape. Each of the plurality of u-bends may have an α value of from about −35° to about 45°. The microserpentine may include a core coated with a conductive coating. The core may include a polymeric material. Various embodiments relate to microelectronic devices and methods of producing the same. The microelectronic devices may include but are not limited to a microelectrode array, a microelectronics packaging, an interconnect, a stretchable sensor, a wearable sensor, a wearable actuator, an in vitro sensor, an in vivo sensor, and combinations thereof.