Abstract: Provided is an acoustic sensor. The acoustic sensor includes: a substrate including sidewall portions and a bottom portion extending from a bottom of the sidewall portions; a lower electrode fixed at the substrate and including a concave portion and a convex portion, the concave portion including a first hole on a middle region of the bottom, the convex portion including a second hole on an edge region of the bottom; diaphragms facing the concave portion of the lower electrode, with a vibration space therebetween; diaphragm supporters provided on the lower electrode at a side of the diaphragm and having a top surface having the same height as the diaphragm; and an acoustic chamber provided in a space between the bottom portion and the sidewall portions below the lower electrode.

Abstract: A coating solution coating solution for forming a transparent dielectric thin film is provided. The coating solution includes a precursor for a first substance including aluminum, a precursor for a second substance including zirconium, and a solvent that dissolves the first and second substances. The solvent is composed of a first solvent and a second solvent.

Abstract: Disclosed are a MEMS microphone and a method of manufacturing the same. The MEMS microphone includes: a substrate; a rear acoustic chamber formed inside a front surface of the substrate; a vibrating plate formed on the substrate and having an exhaust hole; a fixed electrode formed on the vibrating plate; and a fixed electrode support supported by a bottom of the rear acoustic chamber and connected to the fixed electrode through the exhaust hole.

Abstract: Disclosed are an MEMS type semiconductor gas sensor using a microheater having many holes and a method for manufacturing the same. The MEMS type semiconductor gas sensor includes: a substrate of which a central region is etched with a predetermined thickness; a second membrane formed at an upper portion of the central region of the substrate and having many holes; a heat emitting resistor formed on the second membrane and having many holes; a first membrane formed on the second membrane including the heat emitting resistor and having many holes; a sensing electrode formed on the first membrane and having many holes; and a sensing material formed on the sensing electrode.

Abstract: The present inventive concept relates to an analog-digital converter. The analog-digital converter includes a clock generating unit generating a clock signal; a clock delay adjusting unit outputting one of a first clock signal to a Kth clock signal according to a control signal; a capacitive digital-analog converting unit outputting a difference between the analog signal and a reference signal; a comparison unit judging whether an output of the capacitive digital-analog converting unit is 0, a positive number, or a negative number, in response to an output of the clock delay adjusting unit; and an SAR logic unit transferring an output of the comparison unit to the capacitive digital-analog converting unit in response to an output of the clock delay adjusting unit and performing a successive approximation operation to output the N-bit digital signal.

Abstract: The present disclosure relates to a piezoelectric speaker having a weight that enables a frequency response characteristic of the piezoelectric speaker to be uniform by disposing a weight of a flexible material on an acoustic diaphragm or on and below an acoustic diaphragm of the piezoelectric speaker, thereby enhancing flatness of sound. The piezoelectric speaker having the weight includes a piezoelectric device having a piezoelectric layer and an electrode formed on or on and below the piezoelectric layer to apply an electrical signal to the piezoelectric layer; an acoustic diaphragm having a wider area than the piezoelectric device and bonded on one surface of the piezoelectric device; a frame disposed in a form that surrounds a side surface of the acoustic diaphragm; and a weight disposed above the acoustic diaphragm or above and below the acoustic diaphragm on which the piezoelectric device is disposed to thereby control a vibration.

Abstract: Disclosed are ultrasonic wireless power transmitter and receiver apparatuses, and a method for wireless charging thereof.

Abstract: The inventive concept discloses a new temperature sensor structure based on oscillator which is insensitive to a process change and improves an error rate of temperature output. The temperature sensor based on oscillator compares an oscillator circuit structure insensitive to a temperature change with an oscillator circuit structure having a frequency change in proportion to a temperature change to output a relative difference between the two oscillator circuit structures and thereby it is compensated itself. In the temperature sensor based on oscillator, a problem of performance reduction due to an external environment and a process deviation of temperature sensor is improved and an output distortion and temperature nonlinearity are effectively improved. Thus, since the temperature sensor based on oscillator has a structure of high performance, low power and low cost, it can be variously used in a detection equipment of temperature environment.

Abstract: Provided is a voltage supply circuit using a charge pump. The voltage supply circuit enhances charge pump output voltage fluctuation characteristics depending on load variation of a charge pump voltage generator (load regulation characteristics) when receiving an operation power supply voltage of the charge pump through a regulator. The voltage supply circuit is configured to feed back fluctuation of a charge pump output voltage to a charge pump voltage regulator. The fluctuation of the charge pump output voltage is compensated through fluctuation of an output voltage of the charge pump to active enhance the load regulation characteristics.

Abstract: Disclosed is a sound detecting circuit which includes a sensing unit configured to generate an AC signal in response to a sound pressure level of a sound signal; an amplification unit configured to amplify the AC signal; and a bias voltage generating unit configured to generate a bias voltage to be provided to the amplification unit. The bias voltage generating unit comprises a current source configured to provide a power current; and a current-voltage converting circuit configured to convert the power current into the bias voltage and to reduce a noise due to the power current.

Abstract: A method for fabricating an acoustic sensor according to an exemplary embodiment of the present disclosure includes: forming an acoustic sensor unit by forming a lower electrode on an upper portion of a substrate, forming etching holes on the lower electrode, forming a sacrifice layer on an upper portion of the lower electrode, and coupling a diaphragm to an upper portion of the sacrifice layer; coupling a lower portion of the substrate of the acoustic sensor unit to a printed circuit board on which a sound pressure input hole is formed so as to expose the lower portion of the substrate of the acoustic sensor unit to the outside through the sound pressure input hole; attaching a cover covering the acoustic sensor unit on the printed circuit board; etching the substrate of the acoustic sensor unit to form an acoustic chamber; and removing the sacrifice layer.

Abstract: Disclosed are a gas sensor, and a method of manufacturing and using the same. The method includes: forming a detection material on a heater; coating an encapsulant on the detection material; and heating the heater to remove the encapsulant from the detection material when the gas sensor is operated.

Abstract: Disclosed are a MEMS microphone and a method of manufacturing the same. The MEMS microphone includes: a substrate; a rear acoustic chamber formed inside a front surface of the substrate; a vibrating plate formed on the substrate and having an exhaust hole; a fixed electrode formed on the vibrating plate; and a fixed electrode support supported by a bottom of the rear acoustic chamber and connected to the fixed electrode through the exhaust hole.

Abstract: Provided is an acoustic sensor. The acoustic sensor includes: a substrate including sidewall portions and a bottom portion extending from a bottom of the sidewall portions; a lower electrode fixed at the substrate and including a concave portion and a convex portion, the concave portion including a first hole on a middle region of the bottom, the convex portion including a second hole on an edge region of the bottom; diaphragms facing the concave portion of the lower electrode, with a vibration space therebetween; diaphragm supporters provided on the lower electrode at a side of the diaphragm and having a top surface having the same height as the diaphragm; and an acoustic chamber provided in a space between the bottom portion and the sidewall portions below the lower electrode.

Abstract: Disclosed is an electrochemical gas sensor using micro electro mechanical systems (MEMS). The MEMS electrochemical gas sensor includes: a substrate a lower central region of which is etched by a predetermined thickness; a first insulation film formed on the substrate; a heat emitting resistance body formed on the first insulation film; a second insulation film formed on the heat emitting resistance body; a reference electrode formed in an upper central region of the second insulation film; a solid electrolyte formed on the reference electrode; and a detection electrode formed on the solid electrolyte.

Abstract: The present inventive concept relates to an analog-digital converter. The analog-digital converter includes a clock generating unit generating a clock signal; a clock delay adjusting unit outputting one of a first clock signal to a Kth clock signal according to a control signal; a capacitive digital-analog converting unit outputting a difference between the analog signal and a reference signal; a comparison unit judging whether an output of the capacitive digital-analog converting unit is 0, a positive number, or a negative number, in response to an output of the clock delay adjusting unit; and an SAR logic unit transferring an output of the comparison unit to the capacitive digital-analog converting unit in response to an output of the clock delay adjusting unit and performing a successive approximation operation to output the N-bit digital signal.

Abstract: Disclosed are an MEMS type semiconductor gas sensor using a microheater having many holes and a method for manufacturing the same. The MEMS type semiconductor gas sensor includes: a substrate of which a central region is etched with a predetermined thickness; a second membrane formed at an upper portion of the central region of the substrate and having many holes; a heat emitting resistor formed on the second membrane and having many holes; a first membrane formed on the second membrane including the heat emitting resistor and having many holes; a sensing electrode formed on the first membrane and having many holes; and a sensing material formed on the sensing electrode.

Abstract: Disclosed herein is a laser navigation module, including: a light source radiating a laser beam; a housing provided with a window transmitting and reflecting the laser beam radiated from the light source and shielding the introduction of visible rays and provided with a transparent part or a translucent part to radiate light radiated from the inside thereof to the outside; a lighting device mounted in the housing; and a light diffusing member transferring the light radiated from the lighting device and having a groove part formed at an edge of an opposite side of the lighting device.

Abstract: Provided is a method of manufacturing porous metal oxide, the method including: preparing a metal-organic framework (MOF) wherein an ion of a metal to be used as a catalyst is linked to an organic ligand; impregnating the MOF with a precursor solution of metal oxide to be manufactured; and thermally treating the metal oxide precursor solution-impregnated MOF to remove the organic ligand. The inventive method of manufacturing porous metal oxide involves the impregnation of a metal oxide precursor solution in a MOF wherein metal ions are uniformly linked to organic ligands and the thermal treatment (calcination) of the metal oxide precursor solution-impregnated MOF to remove the organic ligands.

Abstract: Disclosed is a piezoelectric speaker including: a piezoelectric layer that converts electrical signals into oscillation and outputs sound; an electrode that is formed on a top or a bottom of the piezoelectric layer to apply the electrical signals to the piezoelectric layer; an acoustic diaphragm that is made of a hetero material including a first acoustic diaphragm and a second acoustic diaphragm and is attached to the bottom of the piezoelectric layer on which the electrode is formed; and a frame attached in a form enclosing a side of the acoustic diaphragm.