Spincoat-fabricated multilayer PDMS-phosphor composites for thermometry

Abstract

Phosphor thermometry offers unique advantages over traditional forms of temperature sensing. Polymer-encapsulated phosphor powders provide versatility and flexibility not achievable when using the thermographic phosphors in powder form. By encapsulating the powder in a polymeric sleeve custom devices with unique properties can be created. Here, the authors report on the design, synthesis, and characterization of the first multilayer thermographic phosphor structure. A thin layer of neat PDMS, Sylgard 184, was sandwiched between two layers of La2O2S:Eu phosphor-doped PDMS. The thicknesses ranged from 0.15 to 4 mm depending on spin speed. The temperature dependent luminescence of the structure was characterized from −40 °C to 75 °C, in a low humidity environmental chamber. Results show suitability for thermometry in this range. In addition, for design guidance, quantitative values for thermal conductivity and stress/strain characteristics versus phosphor loading percentage and temperature were measured. Thermal conductivities ranged from 0.15 W mK−1 for the Sylgard 184 to a value between 0.3 and 0.4 W mK−1 for pure phosphor powder for temperatures from −55 °C to 195 °C. Tensile properties for a strain of up to 1 revealed differences between the different phosphor loadings and phosphor batches. Young’s modulus for the spincoat layered materials was between 1.2 and 1.4 N mm−2 and 0.8 for drop casted samples.

Heat‐triggered poly(siloxane‐urethane)s based on disulfide bonds for self‐healing application

“…Silicone elastomer is widely applied in medical implants, electronics, automobiles, chemical engineering, construction, machinery, and aerospace field, etc . The wide applications of silicone elastomer derived from its unique performances, such as heat‐and‐cold resistance, water resistance, electrical insulating property, chemical stability, physiological inert, and so on . Silicone elastomers have to be crosslinked in application by condensation, polymerization, or hydrosilylation for endowing capability of enough strength .…”

“…[26][27][28] The wide applications of silicone elastomer derived from its unique performances, such as heat-and-cold resistance, 29 water resistance, electrical insulating property, chemical stability, physiological inert, and so on. 27,30 Silicone elastomers have to be crosslinked in application by condensation, polymerization, or hydrosilylation for endowing capability of enough strength. 31 Nevertheless, most of them were irreversible covalent crosslinked networks which were unable to heal by themselves and fail to reprocess.…”

Phosphorescence-Based Flexible and Transparent Optical Temperature-Sensing Skin Capable of Operating in Extreme Environments

“…Compared with the previously reported phosphor-doped PDMS temperature-sensing skin, − the currently developed temperature-sensing skin has a better performance. First of all, its operating temperature range has been improved.…”

“…Given the excellent performance of phosphorescence temperature measurement, some researchers have realized that its application is not limited to traditional industrial fields. In recent years, phosphorescence temperature measurement has begun to appear in the field of biomedicine. , Attempts have been made to make phosphorescence-based flexible temperature sensors. − Except for a few studies on pure ceramic structures with complex preparation methods, most studies have chosen the method of doping phosphorescent particles into a flexible matrix. The currently known flexible matrix materials used for phosphorescence-based flexible temperature sensors include PDMS, − epoxy resin, and silica gel …”

Nanolayer Growth on 3-Dimensional Micro-Objects by Pulsed Laser Deposition

“…In a complementary alternative, we in-situ synthesized Ag-nanoparticle-polymer nanocomposite targets and directly transferred the material and grew plasmonic hybrids [19] for photonic sensing [20]. Extending these concepts to critical optoelectronic devices, we consider here the class of solid-state white-light LEDs (WLEDs) widely used in modern [21] and flexible lighting [22,23], industrial testing and sensing [24]. Among numerous types of phosphors, Y 3 Al 5 O 12 :Ce (YAG:Ce) garnet [25] is a principal representative.…”