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The ability to treat the surface of an object with coatings that counteract the change in radiance resulting from the object’s blackbody emission can be very useful for applications requiring temperature-independent radiance behavior. Such a response is difficult to achieve with most materials except when using phase-change materials, which can undergo a drastic change in their optical response, nullifying the changes in blackbody radiation across a narrow range of temperatures. We report on the theoretical design, giving the possibility of extending the temperature range for temperature-independent radiance coatings by utilizing multiple layers, each comprising a different phase-change material. These designed multilayer coatings are based on thin films of samarium nickelate, vanadium dioxide, and doped vanadium oxide and cover temperatures ranging from room temperature to up to 140 °C. The coatings are numerically engineered in terms of layer thickness and doping, with each successive layer comprising a phase-change material with progressively higher transition temperatures than those below. Our calculations demonstrate that the optimized thin film multilayers exhibit a negligible change in the apparent temperature of the engineered surface. These engineered multilayer films can be used to mask an object’s thermal radiation emission against thermal imaging systems. 

The use of laser induced forward transfer (LIFT) techniques for printing materials for sensor and electronics applications is growing as additive manufacturing expands into the fabrication of functional structures. LIFT is capable of achieving high speed/throughput, high-resolution patterns of a wide range of materials over many types of substrates for applications in flexible-hybrid electronics. In many LIFT applications, the use of a sacrificial or laser-absorbing donor layer is required despite the fact that it can only be used once. This is because the various types of release layers commonly in use with LIFT are completely vaporized when illuminated with a laser pulse. A better solution would be to employ a reusable laser absorbing layer to which the transferable ink or material is attached and then released by a laser pulse without damage to the absorbing layer, therefore allowing its repeated use in subsequent transfers. In this work, we describe the use of two types of reusable laser-absorbing layers for LIFT. One is based on an elastomeric donor layer made from poly(dimethylsiloxane) or PDMS, while the other is based on a ceramic thin film comprised of indium tin oxide (ITO). These release layers have been used at NRL to transfer a wide range of materials including fluids, nanoinks, nanowires and metal foils of varying size and thickness. We will present examples of both PDMS and ITO as donor layers for LIFT and their reusability for laser printing of distinct materials ranging from fluids to solids.