An analytical method to design annular microfilaments with uniform temperature

Abstract Due to their complex electro-thermal characteristics microhotplates used in environmental gas sensors require careful design exhibit uniform temperature and low power dissipation during the expected long time operation. The layout becomes more if multiple operational parameters required by battery operation driver readout logic are considered. In this paper, we describe a simple analytical filament procedure determine dimensions of annular metal exhibiting surface without additional heat distribution layer. presented method operates with cumulative thermal losses towards ambient conduction via membrane. Moreover, it handles requirements like targeted atmospheric environment, supply voltage range, current density, layer thickness its coverage ratio. efficacy is demonstrated electrical characterisation manufactured devices having 150 µm diameter active area. microheater achieves 500 °C 1.4–1.55 V supply. non-uniformity along was measured Spectral pyrometry found decrease from ± 3.5% 1% when raised 530 830 °C.