Abstract: A gas/fluid mass exchange apparatus is disclosed. The apparatus comprises a gas permeable membrane which is arranged to separate a first region for receiving a gas flow, from a second region for receiving a fluid flow. The apparatus further comprises support means which is arranged to maintain the shape and orientation of the membrane.

Abstract: A musical tone generating apparatus employs an array of microresonant structures to generate the harmonic component signals of a musical tone to be generated. The microresonant structures produce high frequency signals which are down converted to audio frequency range by mixing them with a high frequency reference signal. The desired tone color is achieved by modifying the relative amplitudes of the harmonic component signals to produce a desired tone color. A large number of microresonators are preferably integrated on a single integrated circuit substrate to provide a variable tone generating system in a relatively compact environment.