Development of fast response bi-luminophore pressure-sensitive paint by means of an inkjet printing technique

A novel fast response bi-luminophore pressure-sensitive paint (PSP) by inkjet printing of sensor-dot arrays on an anodized aluminum (AA) substrate has been developed for unsteady flow measurements. A bi-luminophore AA-PSP, which is a combination of PSP and temperature-sensitive paint (TSP), is essential for precise pressure measurements, because the PSP result needs the temperature correction. However, a conventional bi-luminophore AA-PSP prepared by a dipping method does not work well due to the interference between the PSP and TSP luminophores. To overcome this problem, we have developed isolated dot arrays of PSP and TSP formed on an anodized aluminum substrate by an inkjet printing method. In this study, platinum tetrakis (pentafluorophenyl) porphyrin (PtTFPP) and ZnS-AgInS2 (ZAIS) were employed as pressure- and temperature-sensitive dyes, respectively. A suitable solvent was chosen for each dye to form the dots with uniform, high luminescence intensity, and high sensitivity. The developed bi-luminophore AA-PSP could simultaneously measure pressure and temperature and could reduce the temperature effect of the PSP from −0.97%/K (without temperature correction) to −0.01%/K (with temperature correction). It showed a pressure response time of 17.8 ± 0.8 μs at 90% pressure rise to a step change of pressure, which is in the same range as a conventional AA-PSP.