Abstract: The present disclosure relates to a microphone driving device and a digital microphone including the same. A microphone driving device according to an embodiment of the inventive concept includes a voltage-to-current converter, a current-to-voltage converter, an analog-to-digital converter, a digital amplification unit, and a gain controller. The voltage-to-current converter converts an acoustic signal to an output current signal based on a gain control signal. The current-to-voltage converter converts the output current signal to an amplified voltage signal. The analog-to-digital converter converts the amplified voltage signal to a digital signal. The digital amplification unit amplifies the digital signal to an amplified digital signal based on the gain control signal. The gain controller generates a gain control signal. The microphone driving device and the digital microphone including the same according to the inventive concept may have a wide dynamic range and reduce the influence of noise.

Abstract: Provided is a pressure sensor including a substrate having a cavity therein, a partition wall disposed in the substrate to surround the cavity, a substrate insulation layer disposed on the top surface of the substrate to cover the cavity, a sensing unit disposed on the substrate insulation layer, and an encapsulation layer disposed on the substrate insulation layer to cover the sensing unit. The cavity may extend from a top surface toward a bottom surface of the substrate, the partition wall may have an inner sidewall exposed by the cavity, and at least a portion of the sensing unit may overlap the cavity when viewed in a plan view.

Abstract: A graphene-based laminate including a doped polymer layer is disclosed. The graphene-based laminate may include a substrate; a graphene layer disposed on the substrate and including at least one layer; and a doped polymer layer disposed on at least one surface of the graphene layer and including an organic dopant.

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 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 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: Provided is a microphone. The microphone includes a substrate including an acoustic chamber, a lower backplate disposed on the substrate, a diaphragm spaced apart from the lower backplate on the lower backplate, the diaphragm having a diaphragm hole passing therethrough, a connection unit disposed on the lower backplate to extend through the diaphragm hole, and an upper backplate disposed on the connection unit, the upper backplate being spaced apart from the diaphragm. Thus, the microphone may be improved in sensitivity and reliability.

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

Abstract: Provided are an acoustic sensor and a method of manufacturing the same. The acoustic sensor includes a substrate including an acoustic chamber, a first hole, and a second hole, penetrating the substrate, a lower electrode pad extended onto a top surface of the substrate while covering a sidewall of the first hole, a diaphragm pad extended onto the top surface of the substrate while covering a sidewall of the second hole, a lower electrode provided on the acoustic chamber and connected to the lower electrode pad, and a diaphragm above the lower electrode while being separated from the lower electrode and connected to the diaphragm pad.

Abstract: Disclosed is a security monitoring method determining whether a trespasser is detected and a position of the trespasser in a set security space and monitoring sound generated at the position of the trespasser by using an acoustic image generated from acoustic signals generated by an acoustic generating device and an acoustic measuring device in an array type. An exemplary embodiment of the present disclosure provides a security monitoring system including: an acoustic generating device that generates acoustic signals; a plurality of acoustic measuring devices that receive the acoustic signals; and an acoustic image processing device that generates an acoustic image using a beamforming algorithm from the acoustic signals received in the plurality of acoustic measuring devices and determines a position of a trespasser by comparing the acoustic image after the trespasser is detected with the acoustic image before the trespasser is detected.

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: 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: 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: Provided is a microphone. The microphone includes a substrate including an acoustic chamber, a lower backplate disposed on the substrate, a diaphragm spaced apart from the lower backplate on the lower backplate, the diaphragm having a diaphragm hole passing therethrough, a connection unit disposed on the lower backplate to extend through the diaphragm hole, and an upper backplate disposed on the connection unit, the upper backplate being spaced apart from the diaphragm. Thus, the microphone may be improved in sensitivity and reliability.

Abstract: Provided is a capacitor-type sensor read-out circuit. The capacitor-type sensor read-out circuit includes: a signal conversion unit outputting a sensor signal inputted from a sensor; a voltage booster generating a bias voltage; and a capacitor-type signal coupling circuit receiving the sensor signal as a feedback, mixing the received sensor signal with the bias voltage, and outputting the mixed signal.

Abstract: Provided are an acoustic sensor and a method of manufacturing the same. The acoustic sensor includes a substrate including an acoustic chamber, a first hole, and a second hole, penetrating the substrate, a lower electrode pad extended onto a top surface of the substrate while covering a sidewall of the first hole, a diaphragm pad extended onto the top surface of the substrate while covering a sidewall of the second hole, a lower electrode provided on the acoustic chamber and connected to the lower electrode pad, and a diaphragm above the lower electrode while being separated from the lower electrode and connected to the diaphragm pad.

Abstract: An MEMS microphone is provided which includes a reference voltage/current generator configured to generate a DC reference voltage and a reference current; a first noise filter configured to remove a noise of the DC reference voltage; a voltage booster configured to generate a sensor bias voltage using the DC reference voltage the noise of which is removed; a microphone sensor configured to receive the sensor bias voltage and to generate an output value based on a variation in a sound pressure; a bias circuit configured to receive the reference current to generate a bias voltage; and a signal amplification unit configured to receive the bias voltage and the output value of the microphone sensor to amplify the output value. The first noise filter comprises an impedance circuit; a capacitor circuit connected to a output node of the impedance circuit; and a switch connected to both ends of the impedance circuit.

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.

Abstract: A graphene-based laminate including a doped polymer layer is disclosed. The graphene-based laminate may include a substrate; a graphene layer disposed on the substrate and including at least one layer; and a doped polymer layer disposed on at least one surface of the graphene layer and including an organic dopant.

Abstract: Provided is a catalytic combustible gas sensor using a porous membrane embedded micro-heater and a micro electro mechanical system (MEMS) technology. The present disclosure provides a gas sensor that is structurally, mechanically, and electrically stable, and has a simple device fabrication process in a MEMS catalytic combustible gas sensor that is miniaturized and also consumes a significantly small amount of power by puncturing a plurality of holes in membranes, a heating resistor, and a sensing electrode, by etching and thereby thermally isolating a substrate by a predetermined thickness through the plurality of holes, and by including a sensing structure formed using a sensing material and a compensation structure formed using a compensation material.