Combinatorial Materials Design Approach to Investigate Adhesion Layer Chemistry for Optimal Interfacial Adhesion Strength

A combinatorial material adhesion study was used to optimize the composition of an adhesion promoting layer for a nanocrystalline diamond (NCD) coating on silicon. Three different adhesion promoting metals, namely W, Cr, and Ta, were selected to fabricate arrays of co-sputtered binary alloy films, with patches of seven different, distinct alloy compositions for each combination, and single element reference films on a single Si wafer (three wafers in total; W–Cr, Cr–Ta, Ta–W). Scratch testing was used to determine the critical failure load and practical work of adhesion for the NCD coatings as a function of adhesion layer chemistry. All tested samples eventually exhibit delamination of the NCD coating, with buckles radiating perpendicularly away from the scratch track. Application of any of the presented adhesion layers yields an increase of the critical failure load for delamination as compared to NCD on Si. While the influence of adhesion layers on the maximum buckle length is less pronounced, shorter buckles are obtained with pure W and Cr–Ta alloy layers. As a general rule, the addition of an adhesion layer showed a 75% improvement in the measured adhesion energies of the NCD films compared to the NCD coating without an adhesion layer, with specific alloys and compositions showing up to 125% increase in calculated practical work of adhesion.

Drama in Structure

Messiaen’s Visions de l’Amen is interpreted as ritual cum drama, enacted by its two pianists. Beginning with the work’s compositional background, this chapter profiles Visions’ two original pianists (Messiaen and Yvonne Loriod), describes the occasion of its premiere, and outlines its extramusical inspiration in Messiaen’s visions of the Amen. Messiaen uses combinatorial means to create Visions’ ritual and drama: repeating, varying, superposing, juxtaposing, combining, and recombining. His combinatorial materials are themes, timbres, and harmonic and rhythmic modules: two types of themes (the Creation theme and the blackbird’s song), two types of timbral elements (birdsong and percussion sounds), and two types of pedals (rhythmic and melodic-harmonic) are discussed, exploring their construction, locations, and functions in Visions. The two pianos themselves, along with the constructs of ritual and drama, are viewed as combinatorial components; the chapter closes by showing how the two pianos, in combination, enact ritual and drama through their relationships.

Combinatorial Investigation of Mechanical Properties of Biomimicked Composites

This study presents the preliminary results of in-situ tests conducted on structural biomimicked composites built by 3D printing. Construction industry is looking seriously into 3D printed structures that can be incorporated into the conventional buildings. Further refinement of materials and processing will lead to the 3D printing of buildings in future. The advantages afforded by 3D printing are unrivaled, creating unprecedented opportunities to express art, economics, environmentally friendly designs, lightweight schemes, among many others. To determine the reliability and suitability of structural composites for use in construction, it is important to test these in shapes, and geometries that are appropriate to 3D printing. Combinatorial materials research allows the fabrication and in-situ testing of composites made by mix and match of various materials. This study focuses on the characterization of mechanical behavior of biomimicked composites fabricated by a 3D printer. To accomplish this, a meter-sized 3D printer was equipped with material dispensers as well as load sensors. Composites were made of various construction materials, adhesive, and reinforcement and subsequently tested by the same printer. The results are presented, and the implications of findings are discussed on their impact on the construction industry.