Suspension of Nanoparticles in SU-8 and Characterization of Nanocomposite Properties

TL;DR

This study explores the incorporation of nanoparticles like gold nanospheres, SWNTs, and diamantane into SU-8 photoresist, analyzing how these additions affect mechanical, electrical, and rheological properties of the resulting nanocomposites.

Contribution

It introduces a method for embedding nanoparticles into SU-8 and characterizes the resulting changes in mechanical and electrical properties, including resistivity and gauge factor.

Findings

Effective modulus and viscosity decrease with diamantane and SWNT addition.

Resistivity of SU-8/SWNT nanocomposites varies with strain, indicating piezoresistive behavior.

Nanocomposites exhibit a gauge factor of approximately 2-4 at 1 wt% SWNT content.

Abstract

Gold nanospheres, single wall carbon nanotubes (SWNT), and diamonoids were phyically incorporated into the negative photoresist SU-8. the mixtures were spin cast onto silicon or aluminium coated silicon wafers. ASTM standard D638 tensile specimens were lithographically patterned in the materials and then released from the substrate using Microchem'Omnicoat or an anodic metal dissolution process. the residual stresses, elastic moduli, and viscosity of the SU-8. Resistivity measurements of SU-8/SWNT nanocomposites were also investigates. We found the effective modulus and viscosity of the SU-8 test specimens decreases with the addition of diamantane and SWNTs. Additionally, the SU-8/SWNT nanocomposites showed changes in resistivity with increased strain, suggesting a gauge factor for the 1 wt% SU-8/SWNT nanocomposite of approximately 2-4.