A flexible gas sensor includes a housing with a predetermined form factor, a photoacoustic gas sensing chamber, and at least one of acoustic, temperature, relative humidity or pressure sensors in combination with processing circuitry which can emulate the characteristic gas response output of a catalytic bead pellistor-type gas sensor in response to a selected gas. The processing circuitry can include a programmable processor and a storage unit. The storage unit can be loaded with data and executable instructions to specify, at least in part, how the signals from the photoacoustic sensor are to be processed by the processing circuitry.