A low power consumption ethanol gas sensor based on a suspended micro-hotplate was fabricated using the droplet guiding deposition technique. FESEM and XRD characteristics show that the host material, SnO₂, maintained the rutile structure and a particle size of ∼40 nm. HRSEM and TEM images illustrate the porous and permeable morphologies of SnO₂/TiO₂ and SnO₂/CNT. The optimal sintering and operating temperatures for detecting ethanol are 450 °C and 300 °C respectively. The response was defined as the ratio of sensor resistance measured in air and ethanol (R_a/R_g), and it was improved by adding 2 wt% TiO₂ and 1 wt% CNT. The responses of SnO₂/TiO₂, SnO₂/CNT, and pure SnO₂ to the lowest concentration of 1 ppm are about 5.2, 4.8 and 2.2 respectively. With an increase in the concentration to 500 ppm ethanol, the responses increase rapidly and reach about 21.5, 19.4 and 15.2. In the low range from 1 ppm to 50 ppm, the variation curves of response are basically linear. The dynamic responses indicate fast response/recovery speed, relatively steady baseline and good repeatability. The experimental results show that the MHP-based sensors made of SnO₂/TiO₂ or SnO₂/CNT have good sensitivity and selectivity for detecting ethanol in a wide range from 1 ppm to 500 ppm while consuming only 12 mW of power.