A method of making an acoustic sensor (e.g., for use in a piezoelectric MEMS microphone) includes forming or providing a mold having one or more grooves in a top surface of the mold that extend in a direction of the length of the mold to a distal end of the mold. The method also includes forming or depositing a structure having one or more piezoelectric layers over the top surface of the mold to define a beam, the distal portion of the beam having a corrugated section including one or more grooves that correspond to the grooves of the mold. The method also includes forming a gap in the structure to define two beams separated by the gap, and releasing the structure from the mold to form one or more cantilever beams that increases an acoustic resistance of the gap between sensors.

This application relates to MEMS devices, especially MEMS capacitive transducers and to processes for forming such MEMS transducer that provide increased robustness and resilience to acoustic shock. The application describes a MEMS transducer having a flexible membrane (101) supported relative to a first surface of a substrate (105) which has one or more cavities therein, e.g. to provide an acoustic volume. A stop structure (401, 402) is positioned so as to be contactable by the membrane when deflected so as to limit the amount of deflection of the membrane. The stop structure defines one or more openings to the one or more substrate cavities and comprises at least one narrow support element (401, 402) within or between said one or more openings. The stop structure thus limits the amount of membrane deflection, thus reducing the stress experienced at the edges and prevents the membrane from contacting a sharp edge of a substrate cavity. As the stop structure comprises narrow support elements any performance impact on the transducer is limited.

Breakup of an electro-acoustic transducer is disrupted by introducing discontinuities that do not conform to a configuration having n-fold radial symmetry. This may be accomplished by using irregular azimuthal spacing and/or by having a junction point of the discontinuities offset relative to the geometric center of the moving surface. The discontinuities may be implemented on one or more of the moving sound producing components, such as on a diaphragm and/or dust cap of the electro-acoustic transducer. A bridging member may be introduced to span the discontinuities to stiffen the sound producing components.

According to an embodiment, a MEMS device includes a deflectable membrane including a first plurality of electrostatic comb fingers, a first anchor structure including a second plurality of electrostatic comb fingers interdigitated with a first subset of the first plurality of electrostatic comb fingers, and a second anchor structure including a third plurality of electrostatic comb fingers interdigitated with a second subset of the first plurality of electrostatic comb fingers. The second plurality of electrostatic comb fingers are offset from the first plurality of electrostatic comb fingers in a first direction and the third plurality of electrostatic comb fingers are offset from the first plurality of electrostatic comb fingers in a second direction, where the first direction is different from the second direction.

A diaphragm for a loudspeaker drive unit or for a microphone includes a rigid dome-shaped member having a thickness that varies from a first thicker thickness at a first location at the periphery of the dome-shaped member to a second thinner thickness at a second location, which is nearer to the center of the dome-shaped member. There is a step-wise change in thickness at a location between the first location and the second location. Having greater thickness at the periphery of the dome-shaped member may improve stiffness of the diaphragm and may allow for an increased break-up frequency. Having thinner material elsewhere in the dome-shaped member may allow the mass of the diaphragm to be kept low and may result in better acoustic sensitivity.

The present invention relates to a loudspeaker which can be arranged to minimise its overall depth while also increasing the breakup frequency and reducing potential rocking vibrations. Accordingly, the present invention is directed to a loudspeaker, comprising a magnet structure, and a voice coil lying within a magnetic field established by the magnet structure and responsive to electrical signals to undergo excursions from a rest position along an axis of motion; a driven body, connected to the voice coil and moveable to project acoustic waves from a front of the loudspeaker; and a suspension for providing a restoring force to the driven body towards the rest position, the suspension extending from an attachment point on the driven body to an attachment point on a fixed portion of the loudspeaker; wherein the driven body comprises a diaphragm and a support structure extending rearwardly from a connection point with the voice coil to a connection point with the suspension located rearward of the frontal part of the magnet structure.

Disclosed are an active noise reduction acoustic unit and a sound-producing unit, the active noise reduction acoustic unit includes a casing; a baseplate which is arranged in the casing and separates the casing into a first accommodating cavity and a second accommodating cavity; the first accommodating cavity and the second accommodating cavity are in communication with each other, the second accommodating cavity being provided therein with a feedback microphone, and the feedback microphone being configured to pick up noise signals; and the first accommodating cavity is provided therein with a moving iron speaker which can vibrate and produce sound according to the noise signals.

The present disclosure relates to a loudspeaker transducer comprising a diaphragm (112), a frame (120), an inner suspensions element (118) and an outer suspension element (110). The diaphragm (112) comprises a portion turning inwards (102) towards the frame (120). The outer suspension element (110) is located closer than the inner suspension element (118) to the main opening of the frame through which the loudspeaker transducer radiates sound. The inner suspension element (118) is connected to the frame (120) and the inward turning portion (102). The inner suspension element (118) is connected to the inward turning portion (102) at an outer end (203) of the diaphragm.

A diaphragm applied to a sound producing device, a sound producing device, and a method for assembling the same. The diaphragm comprises a film layer prepared by means of a crosslinking reaction of at least one of an ethylene-acrylate copolymer and an ethylene-acrylate-carboxylic acid copolymer. The molecular structure of the diaphragm comprises a vinyl-acrylic group. The group causes the material to have a less symmetrical chemical structure, a reduced tacticity and an increased steric hindrance, such that the diaphragm has a high loss factor, and the sound producing device achieves a good damping effect.

This application relates to MEMS devices, especially MEMS capacitive transducers and to processes for forming such MEMS transducer that provide increased robustness and resilience to acoustic shock. The application describes a MEMS transducer having a flexible membrane (101) supported relative to a first surface of a substrate (105) which has one or more cavities therein, e.g. to provide an acoustic volume. A stop structure (401, 402) is positioned so as to be contactable by the membrane when deflected so as to limit the amount of deflection of the membrane. The stop structure defines one or more openings to the one or more substrate cavities and comprises at least one narrow support element (401, 402) within or between said one or more openings. The stop structure thus limits the amount of membrane deflection, thus reducing the stress experienced at the edges and prevents the membrane from contacting a sharp edge of a substrate cavity. As the stop structure comprises narrow support elements any performance impact on the transducer is limited.