US Patent 9995700 Heater structure for a sensor device

The sensor device comprises a hotplate on a membrane. The hotplate is heated by a N-fold rotationally symmetric heater structure having N>1 heater elements of identical design. Each heater element comprises an inner section, an intermediate section and an outer section arranged in series, with the inner section having a larger electrical cross section than the outer section. This design allows to heat the hotplate to a homogeneous temperature at moderate supply voltages.