An aerosol generator comprises: a reservoir configured to contain a liquid medium; a heating body comprising a plurality of channels and an electrically-conductive sheet, the sheet having a first surface and an opposite second surface; and an electric power unit configured to inject pulses of electric current through the sheet. The channels are disposed in the sheet and extending through the sheet from the first surface of the sheet to the opposite second surface of the sheet. The channels are configured for providing directional flow of a vapor from the channels. In some embodiments, the channels have variable width along the length. The sheet material includes heavily doped silicon. The electric power unit provides correlation of the pulse parameters with the thermal time constant of the heating body for pulsed operation of the heating body. The aerosol generator produces dense inhalable aerosol at reduced hazardous risks and is manufactured more standardized at a low cost.