Henkel Corp. (Rocky Hill, Conn.) has introduced Loctite 3355 light-curing adhesive, a pre-activated epoxy designed for colored and opaque substrates, such as composites, plastics, metal, glass and ceramics, that cannot transmit light. The single-component, medium-viscosity adhesive requires no mixing and is applied to opaque materials, then exposed to UV light (254 nm to 365 nm wavelength) for 5 to 60 seconds prior to assembly. During cure, the material reportedly exhibits very low shrinkage, a plus in assemblies where alignment of small parts is critical. According to the company, the acid-free, low out-gassing formulation will not corrode or contaminate sensitive components, including electronics. It is said to be suitable for bonding and shallow potting of optical connectors, fibers, lasers, lenses, prisms and electronic devices (e.g, laptops and printers.)