Abstract: A carbon nanotube filter, a use for a carbon nanotube filter and a method of forming a carbon nanotube filter. The method including (a) providing a carbon source and a carbon nanotube catalyst; (b) growing carbon nanotubes by reacting the carbon source with the nanotube catalyst; (c) forming chemically active carbon nanotubes by forming a chemically active layer on the carbon nanotubes or forming chemically reactive groups on sidewalls of the carbon nanotubes; and (d) placing the chemically active nanotubes in a filter housing.

Abstract: A carbon nanotube filter. The filter including a filter housing; and chemically active carbon nanotubes within the filter housing, the chemically active carbon nanotubes comprising a chemically active layer formed on carbon nanotubes or comprising chemically reactive groups on sidewalls of the carbon nanotubes; and media containing the chemically active carbon nanotubes.

Abstract: A carbon nanotube filter. The filter including a filter housing; and chemically active carbon nanotubes within the filter housing, the chemically active carbon nanotubes comprising a chemically active layer formed on carbon nanotubes or comprising chemically reactive groups on sidewalls of the carbon nanotubes; and media containing the chemically active carbon nanotubes.

Abstract: A carbon nanotube filter. The filter including a filter housing; and chemically active carbon nanotubes within the filter housing, the chemically active carbon nanotubes comprising a chemically active layer formed on carbon nanotubes or comprising chemically reactive groups on sidewalls of the carbon nanotubes; and media containing the chemically active carbon nanotubes.

Abstract: An exposure system for exposing a photoresist layer on a top surface of a wafer to light. The exposure system including: an environment chamber containing a light source, one or more focusing lenses, a mask holder, a slit and a wafer stage, the light source, all aligned to an optical axis, the wafer stage moveable in two different orthogonal directions orthogonal to the optical axis, the mask holder and the slit moveable in one of the two orthogonal directions; a filter in a sidewall of the environment chamber, the filter including: a filter housing containing chemically active carbon nanotubes, the chemically active carbon nanotubes comprising a chemically active layer formed on carbon nanotubes or comprising chemically reactive groups on sidewalls of the carbon nanotubes; and means for forcing air or inert gas first through the filter then into the environment chamber and then out of the environment chamber.

Abstract: A carbon nanotube filter, a use for a carbon nanotube filter and a method of forming a carbon nanotube filter. The method including (a) providing a carbon source and a carbon nanotube catalyst; (b) growing carbon nanotubes by reacting the carbon source with the nanotube catalyst; (c) forming chemically active carbon nanotubes by forming a chemically active layer on the carbon nanotubes or forming chemically reactive groups on sidewalls of the carbon nanotubes; and (d) placing the chemically active nanotubes in a filter housing.

Abstract: A carbon nanotube filter, a use for a carbon nanotube filter and a method of forming a carbon nanotube filter. The method including (a) providing a carbon source and a carbon nanotube catalyst; (b) growing carbon nanotubes by reacting the carbon source with the nanotube catalyst; (c) forming chemically active carbon nanotubes by forming a chemically active layer on the carbon nanotubes or forming chemically reactive groups on sidewalls of the carbon nanotubes; and (d) placing the chemically active nanotubes in a filter housing.

Abstract: An exposure system for exposing a photoresist layer on a top surface of a wafer to light. The exposure system including: an environment chamber containing a light source, one or more focusing lenses, a mask holder, a slit and a wafer stage, the light source, all aligned to an optical axis, the wafer stage moveable in two different orthogonal directions orthogonal to the optical axis, the mask holder and the slit moveable in one of the two orthogonal directions; a filter in a sidewall of the environment chamber, the filter including: a filter housing containing chemically active carbon nanotubes, the chemically active carbon nanotubes comprising a chemically active layer formed on carbon nanotubes or comprising chemically reactive groups on sidewalls of the carbon nanotubes; and means for forcing air or inert gas first through the filter then into the environment chamber and then out of the environment chamber.

Abstract: A carbon nanotube filter. The filter including a filter housing; and chemically active carbon nanotubes within the filter housing, the chemically active carbon nanotubes comprising a chemically active layer formed on carbon nanotubes or comprising chemically reactive groups on sidewalls of the carbon nanotubes; and media containing the chemically active carbon nanotubes.

Abstract: A carbon nanotube filter, a use for a carbon nanotube filter and a method of forming a carbon nanotube filter. The method including (a) providing a carbon source and a carbon nanotube catalyst; (b) growing carbon nanotubes by reacting the carbon source with the nanotube catalyst; (c) forming chemically active carbon nanotubes by forming a chemically active layer on the carbon nanotubes or forming chemically reactive groups on sidewalls of the carbon nanotubes; and (d) placing the chemically active nanotubes in a filter housing.

Abstract: A digital hearing aid is provided that includes front and rear microphones, a sound processor, and a speaker. Embodiments of the digital hearing aid include an occlusion subsystem, and a directional processor and headroom expander. The front microphone receives a front microphone acoustical signal and generates a front microphone analog signal. The rear microphone receives a rear microphone acoustical signal and generates a rear microphone analog signal. The front and rear microphone analog signals are converted into the digital domain, and at least the front microphone signal is coupled to the sound processor. The sound processor selectively modifies the signal characteristics and generates a processed signal. The processed signal is coupled to the speaker which converts the signal to an acoustical hearing aid output signal that is directed into the ear canal of the digital hearing aid user.

Abstract: A vent configuration for a hearing instrument comprises a vent tube having a length and a vent opening, and at least one cell positioned around the periphery of the vent tube. The at least one cell is closed at a first inner end and open at an outer end, which is adjacent the vent opening. The cell is a tube that extends around the periphery of the vent tube along a portion of the length of the vent tube. A hearing instrument incorporating the vent configuration is also included.

Abstract: The present invention increases the aperture size of a microphone array by introducing a diffracting structure into the interior of a microphone array. The diffracting structure within the array modifies both the amplitude and phase of the acoustic signal reaching the microphones. The diffracting structure increases acoustic shadowing along with the signal's travel time around the structure. The diffracting structure in the array effectively increases the aperture size of the array and thereby increases the directivity of the array. Constructing the surface of the diffracting structure such that surface waves can form over the surface further increases the travel time and modifies the amplitude of the acoustical signal thereby allowing a larger effective aperture for the array.

Abstract: A system for receiving and processing audio signals includes a handheld audio processing device and an audio receiver unit. The handheld audio processing device has a plurality of microphones located on the handheld audio processing device that define a surface and at least a pair of intersecting axes on the surface where each of the axes is defined by at least two microphones. The handheld audio processing device also has a processing subsystem configured to receive audio signals generated by the plurality of microphones and to spatially filter the audio signals and a transmitter configured to transmit the spatially filtered audio signals. The audio receiver unit is located remote from the handheld audio processing device and configured to receive the spatially filtered audio signals transmitted by the handheld audio transmitter.

Abstract: A method and apparatus for reducing the acoustic coupling between a sound receiving transducer and a sound transmitting transducer is disclosed. A housing, wherein the receiving transducer and the transmitting transducer are mounted, is provided to increase the acoustic separation between the receiving transducer and the transmitting transducer. The housing has a surface, which may have an acoustic impedance condition, which is preferably resistive. The housing may further act as a barrier structure between the receiving transducer and the transmitting transducer.

Abstract: The present invention increases the aperture size of a microphone array by introducing a diffracting structure into the interior of a microphone array. The diffracting structure within the array modifies both the amplitude and phase of the acoustic signal reaching the microphones. The diffracting structure increases acoustic shadowing along with the signal's travel time around the structure. The diffracting structure in the array effectively increases the aperture size of the array and thereby increases the directivity of the array. Constructing the surface of the diffracting structure such that surface waves can form over the surface further increases the travel time and modifies the amplitude of the acoustical signal thereby allowing a larger effective aperture for the array.

Abstract: A digital hearing aid is provided that includes front and rear microphones, a sound processor, and a speaker. Embodiments of the digital hearing aid include an occlusion subsystem, and a directional processor and headroom expander. The front microphone receives a front microphone acoustical signal and generates a front microphone analog signal. The rear microphone receives a rear microphone acoustical signal and generates a rear microphone analog signal. The front and rear microphone analog signals are converted into the digital domain, and at least the front microphone signal is coupled to the sound processor. The sound processor selectively modifies the signal characteristics and generates a processed signal. The processed signal is coupled to the speaker which converts the signal to an acoustical hearing aid output signal that is directed into the ear canal of the digital hearing aid user.

Abstract: A digital hearing aid is provided that includes front and rear microphones, a sound processor, and a speaker. Embodiments of the digital hearing aid include an occlusion subsystem, and a directional processor and headroom expander. The front microphone receives a front microphone acoustical signal and generates a front microphone analog signal. The rear microphone receives a rear microphone acoustical signal and generates a rear microphone analog signal. The front and rear microphone analog signals are converted into the digital domain, and at least the front microphone signal is coupled to the sound processor. The sound processor selectively modifies the signal characteristics and generates a processed signal. The processed signal is coupled to the speaker which converts the signal to an acoustical hearing aid output signal that is directed into the ear canal of the digital hearing aid user.

Abstract: A vent configuration for a hearing instrument comprises a vent tube having a length and a vent opening, and at least one cell positioned around the periphery of the vent tube. The at least one cell is closed at a first inner end and open at an outer end, which is adjacent the vent opening. The cell is a tube that extends around the periphery of the vent tube along a portion of the length of the vent tube. A hearing instrument incorporating the vent configuration is also included.

Abstract: A scanning probe microscope probe is formed by depositing probe material in a mold that has a cavity in a shape and of a size of the desired form of the scanning probe microscope probe that is being fabricated. In the preferred embodiment, the cavity is formed by lithographically defining, in the body of the mold, the shape and the size of the desired scanning probe microscope probe and etching the body of the mold to form the cavity. Prior to depositing the probe material in the cavity in the mold, the cavity is lined with a release layer which, upon activation after the probe has been formed, permits removal of the probe.