This paper describes the transfer of thin gold films deposited on rigid silicon substrates to polydimethylsiloxane (PDMS) with reliable and strong bonding. Modification of the Au surfaces with (3-mercaptopropyl)trimethoxysilane (MPTMS) as a molecular adhesive was carried out to promote adhesion between Au and PDMS. The degree of bonding with respect to the concentration of MPTMS, treatment time and methods of deposition was investigated by a simple adhesion test using two different adhesive tapes. The effect of hydrolysis of MPTMS is discussed based on the bonding mechanism of MPTMS to the PDMS prepolymer. Also, the adsorption of MPTMS on Au deposited by different methods is discussed. The results indicate that liquid deposition of MPTMS provides the strongest adhesion between Au and PDMS among the different deposition methods and the different linker molecules. Based on these studies, the Au patterns with linewidth of less 2 µm were successfully transferred to PDMS with reliable and strong bonding in a full 3 inch wafer scale, using a dry peel-off process.

This paper presents a cost-effective interference lithography system that uses a 405 nm AlInGaN semiconductor laser. This method is cost-effective because the AlInGaN semiconductor laser has a long coherence length (∼20 m) and low price (e.g. only 1/3 that of the HeCd laser). This system successfully fabricated uniform nano-periodic patterns (line, dot and hole) in a photoresist (PR) over a 2 × 2 cm sample area. The PR patterns agreed well with simulations. Tall silicon nano-structures were fabricated by deep reactive ion etching (DRIE) using a PR pattern as a direct etch mask layer. Aspect ratios of 25 with smooth and vertical sidewalls were achieved after 32 DRIE cycles.

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The couple Calix[4]arene-1,3-O-diphosphorous acid (C4diP) and zinc ions (Zn 2+ ) acts as a synergistic DNA binder. Silicon NanoTweezer (SNT) measurements show an increase in the mechanical stiffness of DNA bundles by a factor of >150, at Zn 2+ to C4diP ratios above 8, as compared to Zinc alone whereas C4diP alone decreases the stiffness of DNA. Electroanalytical measurements using 3D printed devices demonstrate a progression of events in the assembly of C4diP on DNA promoted by zinc ions. A mechanism at the molecular level can be deduced in which C4diP initially coordinates to DNA by phosphate-phosphate hydrogen bonds or in the presence of Zn 2+ by Zn 2+ bridging coordination of the phosphate groups. Then, at high ratios of Zn 2+ to C4diP, interdigitated dimerization of C4diP is followed by cross coordination of DNA strands through Zn 2+ /C4diP inter-strand interaction. The sum of these interactions leads to strong stiffening of the DNA bundles and increased inter-strand binding.