Adhesive curing through low-voltage activation

Instant curing adhesives typically fall within three categories, being activated by either light (photocuring), heat (thermocuring) or chemical means. These curing strategies limit applications to specific substrates and can only be activated under certain conditions. Here we present the development of an instant curing adhesive through low-voltage activation. The electrocuring adhesive is synthesized by grafting carbene precursors on polyamidoamine dendrimers and dissolving in aqueous solvents to form viscous gels. The electrocuring adhesives are activated at 2V versus Ag/AgCl, allowing tunable crosslinking within the dendrimer matrix and on both electrode surfaces. As the applied voltage discontinued, crosslinking immediately terminated. Thus, crosslinking initiation and propagation are observed to be voltage and time dependent, enabling tuning of both material properties and adhesive strength. The electrocuring adhesive has immediate implications in manufacturing and development of implantable bioadhesives

Light-microgel interaction in resonant nanostructures

Combination of responsive microgels and photonic resonant nanostructures represents an intriguing technological tool for realizing tunable and reconfigurable platforms, especially useful for biochemical sensing applications. Interaction of light with microgel particles during their swelling/shrinking dynamics is not trivial because of the inverse relationships between their size and refractive index. In this work, we propose a reliable analytical model describing the optical properties of closed-packed assembly of surface-attached microgels, as a function of the external stimulus applied. The relationships between the refractive index and thickness of the equivalent microgel slab are derived from experimental observations based on conventional morphological analysis. The model is first validated in the case of temperature responsive microgels integrated on a plasmonic lab-on-fiber optrode, and also implemented in the same case study for an optical responsivity optimization problem. Overall, our model can be extended to other photonic platforms and different kind of microgels, independently from the nature of the stimulus inducing their swelling