Drastic Improvements in Bonding of Fiber Reinforced Multifunctional Composites

Achievement of a dramatic increase in the bond strength in the adhesive and composite/adhesive interfaces of existing fiber reinforced composite material joints and structures suitable for various NASA applications is the main goal of this project. The proposed technology developed at Integrated Micro Sensors Inc is based on laser-assisted fabrication of Micro Column Arrays (MCA) on the surface of the two materials prior to bonding. There are several advantages of the MCA technology in the drastic improvement of any bond: (i) mechanical strength increases due to interlocking of the adhesive or brazing material between micro columns, (ii) the bond strength increases due to the increase of the specific surface area by more than an order of magnitude, (iii) stability increases due to the inherent elasticity of the micro cones during a deformation, (iv) increase in the bond durability because of the repeated bend contours of the surface preventing hydrothermal failure, (v) wettability of the material surface significantly improves due to the highly developed surface morphology at the micro and submicron level and changes in local chemistry as a result of surface oxidation. Based on the feasibility proven in the Phase I project, this Phase II project will focus on implementation of the proposed technology for newest materials developed up to date and scaling of the proposed technology to large area and complex shape FRP composite structural joints. The investigation of the approach based on using the bond interface electrical properties for joint health monitoring initiated in the Phase I project, will be further developed into viable transducer device concepts.