A single MEMS thermal conductivity sensor based system capable of simultaneously measuring an air containing hydrogen and water vapor concentrations is described. The hydrogen and water vapor have different temperature coefficients of thermal conductivities and the sensor calculates their concentrations by their contributions to the total thermal conductivity of the air containing hydrogen and water vapor at different modulation temperatures of the sensor. The sensor comprises a one-dimensional gas heat conduction chamber is used to measure the temperature difference between the heat source on the top and heat sink on the bottom of the chamber. The hydrogen and water vapor concentrations can be calculated using the measured thermal conductivities of the air contained hydrogen and water vapor at different modulation temperatures of the sensor.
A piezoelectric MEMS resonator is provided. The resonator comprises a single crystal silicon microstructure suspended over a buried cavity created in a silicon substrate and a piezoelectric resonance structure located on the microstructure. The resonator is designed and fabricated based on porous silicon related technologies including selective formation and etching of porous silicon in silicon substrate, porous silicon as scarified material for surface micromachining and porous silicon as substrate for single crystal silicon epitaxial growth. All these porous silicon related technologies are compatible with CMOS technologies and can be conducted in a standard CMOS technologies platform.
H03H 9/17 - Constructional features of resonators consisting of piezoelectric or electrostrictive material having a single resonator
H03H 3/02 - Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks
H03H 9/13 - Driving means, e.g. electrodes, coils for networks consisting of piezoelectric or electrostrictive materials
H03H 3/007 - Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks
H03H 9/24 - Constructional features of resonators of material which is not piezoelectric, electrostrictive, or magnetostrictive
H03H 9/15 - Constructional features of resonators consisting of piezoelectric or electrostrictive material
A multi-purpose Micro-Electro-Mechanical Systems (MEMS) thermopile sensor able to use as a thermal conductivity sensor, a Pirani vacuum sensor, a thermal flow sensor and a non-contact infrared temperature sensor, respectively. The sensor comprises a rectangular membrane created in a silicon substrate which has a thin polysilicon layer and a thin residual thermal reorganized porous silicon layer both attached on its back side, and configured to have its three sides clamped to the frame formed in the silicon substrate which surrounds and supports the membrane and the other side free to the frame, a cavity created in the silicon substrate, positioned under the membrane and having its flat bottom opposite to the membrane, its three side walls shaped as curved planes and the other side wall shaped as a vertical plane, a heater or an infrared absorber positioned on the membrane, close to and parallel with the free side of the membrane and a thermopile positioned on the membrane and consists of several thermocouples connected in series and having its hot junctions close to the heater and its cold junctions extended to the frame.
B81C 1/00 - Manufacture or treatment of devices or systems in or on a substrate
H01L 35/04 - Structural details of the junction; Connections of leads
H01L 35/34 - Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
G01K 7/02 - Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat using thermoelectric elements, e.g. thermocouples
G01L 21/12 - Vacuum gauges by measuring variations in the heat conductivity of the medium, the pressure of which is to be measured measuring changes in electric resistance of measuring members, e.g. of filamentsVacuum gauges of the Pirani type
G01J 5/12 - Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors using thermoelectric elements, e.g. thermocouples
G01F 1/684 - Structural arrangementsMounting of elements, e.g. in relation to fluid flow
5.
Unburned tobacco controller in true response to smoker's puff process
The present invention relates to an unburned tobacco controller in true response to smoker's puff process. The unburned tobacco controller comprises a MEMS thermal flow sensor and a microcontroller. With the thermal flow sensor, the controller can duplicate a whole smoker's puff process including puff start, puff stop, single puff duration, single puff volume, single puff interval, total puff volume, total puff duration, total puff interval and total puff number. The microcontroller with several embedded programs so that a tobacco roll can be heated to release nicotine-contained smokes meeting the habits and needs of the smoker and making the smoker feel, sense and experience like a conventional tobacco product.
A24F 47/00 - Smokers’ requisites not otherwise provided for
H04W 4/80 - Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication
A single silicon wafer micromachined thermal conduction sensor is described. The sensor consists of a heat transfer cavity with a flat bottom and an arbitrary plane shape, which is created in a silicon substrate. A heated resistor with a temperature dependence resistance is deposed on a thin film bridge, which is the top of the cavity. A heat sink is the flat bottom of the cavity and parallel to the bridge completely. The heat transfer from the heated resistor to the heat sink is modulated by the change of the thermal conductivity of the gas or gas mixture filled in the cavity. This change can be measured to determine the composition concentration of the gas mixture or the pressure of the air in a vacuum system.
G01N 25/18 - Investigating or analysing materials by the use of thermal means by investigating thermal conductivity
B81C 1/00 - Manufacture or treatment of devices or systems in or on a substrate
G01N 27/18 - Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of an electrically-heated body in dependence upon change of temperature caused by changes in the thermal conductivity of a surrounding material to be tested
A vacuum-cavity-insulated flow sensor and related fabrication method are described. The sensor comprises a porous silicon wall with numerous vacuum-pores which is created in a silicon substrate, a porous silicon membrane with numerous vacuum-pores which is surrounded and supported by the porous silicon wall, and a cavity with a vacuum-space which is disposed beneath the porous silicon membrane and surrounded by the porous silicon wall. The fabrication method includes porous silicon formation and silicon polishing in HF solution.
B81C 1/00 - Manufacture or treatment of devices or systems in or on a substrate
H01L 35/34 - Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
G01F 1/684 - Structural arrangementsMounting of elements, e.g. in relation to fluid flow
G01F 1/688 - Structural arrangementsMounting of elements, e.g. in relation to fluid flow using a particular type of heating, cooling or sensing element
A MEMS vaporizer is described which can be used for electronic cigarettes. The vaporizer mainly composes: a silicon substrate, a micro-channel array, a membrane suspending over the micro-channel array and supported by the silicon substrate, a resistance heater and a resistance temperature sensor are disposed on the membrane. Since the vaporizer is a silicon-based integrated actuator which provides advantages including small size, compact structure, lower power consumption, lower cost, increased reliability, higher precision, and more environmental friendliness.
A24F 47/00 - Smokers’ requisites not otherwise provided for
B23K 31/02 - Processes relevant to this subclass, specially adapted for particular articles or purposes, but not covered by any single one of main groups relating to soldering or welding
An electronic cigarette with a thermal flow sensor based controller is provided which comprises a housing; a battery, a controller assembly; an air inlet for allowing air to enter into the housing, a mouthpiece; a fluid reservoir; an atomizer; at least a light emitting diode; and a display. The thermal flow sensor is fabricated using micro-electro-mechanical systems (MEMS) technologies which is amenable to create the electronic cigarette with a thermal flow sensor based controller having stable evaporated liquid delivering, immediately response to smoker inhalation, like normal cigarette inhalation resistance, low power consumption, and no accidental actuation take place.
A single silicon wafer micromachined thermal conduction sensor is described. The sensor consists of a heat transfer cavity with a flat bottom and an arbitrary plane shape, which is created in a silicon substrate. A heated resistor with a temperature dependence resistance is deposed on a thin film bridge, which is the top of the cavity. A heat sink is the flat bottom of the cavity and parallel to the bridge completely. The heat transfer from the heated resistor to the heat sink is modulated by the change of the thermal conductivity of the gas or gas mixture filled in the cavity. This change can be measured to determine the composition concentration of the gas mixture or the pressure of the air in a vacuum system.
G01N 25/18 - Investigating or analysing materials by the use of thermal means by investigating thermal conductivity
B81C 1/00 - Manufacture or treatment of devices or systems in or on a substrate
G01N 27/18 - Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of an electrically-heated body in dependence upon change of temperature caused by changes in the thermal conductivity of a surrounding material to be tested
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