A flexible sensor system in foil for combined absolute pressure and flow velocity measurements

This work reports on a foil integrated, flexible pressure- and hot-film sensor system for measuring flows over curved surfaces. The miniaturized rigid silicon piezoresistive pressure transducer with enclosed reference cavity allows absolute pressure sensing. Together with a foil-based hot-film transducer both transducers are embedded in a combination of thin epoxy resin with polyimide. This in-foil sensor system is surface passive and waterproof and can be bent to a radius of 20 mm while maintaining full functionality.