Soft network composite materials with deterministic and bio-inspired designs.

Hard and soft structural composites found in biology provide inspiration for the design of advanced synthetic materials. Many examples of bio-inspired hard materials can be found in the literature; far less attention has been devoted to soft systems. Here we introduce deterministic routes to low-modulus thin film materials with stress/strain responses that can be tailored precisely to match the non-linear properties of biological tissues, with application opportunities that range from soft biomedical devices to constructs for tissue engineering.

Tailoring surface plasmons of high-density gold nanostar assemblies on metal films for surface-enhanced Raman spectroscopy.

Plasmonic systems based on metal nanoparticles on a metal film have generated great interest for surface-enhanced Raman spectroscopy (SERS) chemical sensors. In this study, we describe the fabrication of ultrasensitive SERS substrates based on high-density gold nanostar assemblies on silver films with tailored surface plasmons, where multiple field enhancements from particle-film and interparticle plasmon couplings and lightening rod effects of sharp tips of nanostars contribute to the enormous Raman enhancements. We show that the interplay between interparticle and particle-film plasmon couplings of high-density gold nanostars (GNSs) on metal and dielectric films as a function of interparticle separation can be tailored to provide maximum SERS effects.