Pressure Differences from Clear Aligner Movements Assessed by Pressure Sensors

Objectives. In this study, a clear aligner was moved at intervals of 0.25 mm and pressure variations were assessed using a sensor. Methods. The model used for producing the clear aligner was created using a 3-dimensional printer. A clear, circular thermoplastic of 0.75 mm thickness was used for making the clear aligner using the vacuum forming method. A pressure sensor was used to assess the pressure in the device, and the variation in the sheet pressure was statistically analyzed tooth movement using the clear aligner, moving at an interval of 0.25 mm, is recommended. Results. The results of pressure sensor assessment showed that the pressure of the devices with 0.25 mm and 1.00 mm movements was identical to that of the device with 0 mm movement. In other words, the pressure sensor could not distinguish the pressure of devices that moved 0.25 mm and 1.00 mm. Conclusions. This experiment demonstrated that a movement of more than 0.50 mm is needed to apply the appropriate pressures needed for orthodontics in a clear polymer sheet.

Download Full-text

Development of circuit solution and design of capacitive pressure sensor array for applied robotics

Robotics and Technical Cybernetics ◽

10.31776/rtcj.8406 ◽

2020 ◽

Vol 8 (4) ◽

pp. 296-307

Author(s):

Konstantin Krestovnikov ◽

Aleksei Erashov ◽

Аleksandr Bykov

Keyword(s):

Pressure Sensor ◽

Output Signal ◽

Sensor Array ◽

Applied Pressure ◽

Pressure Sensors ◽

Fine Tuning ◽

Capacitive Pressure Sensor ◽

Cell Parameters ◽

Linear Pattern ◽

Sensor Structure

This paper presents development of pressure sensor array with capacitance-type unit sensors, with scalable number of cells. Different assemblies of unit pressure sensors and their arrays were considered, their characteristics and fabrication methods were investigated. The structure of primary pressure transducer (PPT) array was presented; its operating principle of array was illustrated, calculated reference ratios were derived. The interface circuit, allowing to transform the changes in the primary transducer capacitance into voltage level variations, was proposed. A prototype sensor was implemented; the dependency of output signal power from the applied force was empirically obtained. In the range under 30 N it exhibited a linear pattern. The sensitivity of the array cells to the applied pressure is in the range 134.56..160.35. The measured drift of the output signals from the array cells after 10,000 loading cycles was 1.39%. For developed prototype of the pressure sensor array, based on the experimental data, the average signal-to-noise ratio over the cells was calculated, and equaled 63.47 dB. The proposed prototype was fabricated of easily available materials. It is relatively inexpensive and requires no fine-tuning of each individual cell. Capacitance-type operation type, compared to piezoresistive one, ensures greater stability of the output signal. The scalability and adjustability of cell parameters are achieved with layered sensor structure. The pressure sensor array, presented in this paper, can be utilized in various robotic systems.

Download Full-text

Simulation and Nonlinearity Optimization of a High-Pressure Sensor

Sensors ◽

10.3390/s20164419 ◽

2020 ◽

Vol 20 (16) ◽

pp. 4419

Author(s):

Ting Li ◽

Haiping Shang ◽

Weibing Wang

Keyword(s):

High Pressure ◽

Pressure Sensor ◽

Pressure Sensors ◽

Original Model ◽

Ansys Software ◽

Nonlinear Error ◽

Sensor Model ◽

Optimized Model ◽

Simulation Results ◽

Better Than

A pressure sensor in the range of 0–120 MPa with a square diaphragm was designed and fabricated, which was isolated by the oil-filled package. The nonlinearity of the device without circuit compensation is better than 0.4%, and the accuracy is 0.43%. This sensor model was simulated by ANSYS software. Based on this model, we simulated the output voltage and nonlinearity when piezoresistors locations change. The simulation results showed that as the stress of the longitudinal resistor (RL) was increased compared to the transverse resistor (RT), the nonlinear error of the pressure sensor would first decrease to about 0 and then increase. The theoretical calculation and mathematical fitting were given to this phenomenon. Based on this discovery, a method for optimizing the nonlinearity of high-pressure sensors while ensuring the maximum sensitivity was proposed. In the simulation, the output of the optimized model had a significant improvement over the original model, and the nonlinear error significantly decreased from 0.106% to 0.0000713%.

Download Full-text

Enhanced piezocapacitive response in zinc oxide tetrapod–poly(dimethylsiloxane) composite dielectric layer for flexible and ultrasensitive pressure sensor

Nanoscale ◽

10.1039/d0nr06743a ◽

2021 ◽

Vol 13 (12) ◽

pp. 6076-6086

Author(s):

Gen-Wen Hsieh ◽

Shih-Rong Ling ◽

Fan-Ting Hung ◽

Pei-Hsiu Kao ◽

Jian-Bin Liu

Keyword(s):

Zinc Oxide ◽

Pressure Sensor ◽

Dielectric Layer ◽

Pressure Sensors ◽

Dielectric Matrix ◽

First Time

Zinc oxide tetrapod is introduced for the first time within a poly(dimethylsiloxane) dielectric matrix for the formation of ultrasensitive piezocapacitive pressure sensors.

Download Full-text

CMOS-MEMS Based Current Mirror MOSFET Embedded Pressure Sensor for Healthcare and Biomedical Applications

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.647.315 ◽

2013 ◽

Vol 647 ◽

pp. 315-320 ◽

Cited By ~ 6

Author(s):

Pradeep Kumar Rathore ◽

Brishbhan Singh Panwar

Keyword(s):

Pressure Sensor ◽

Biomedical Applications ◽

Circuit Simulation ◽

Applied Pressure ◽

Pressure Sensors ◽

Cmos Technology ◽

Current Mirror ◽

Sensing Element ◽

Pressure Sensing ◽

Cmos Mems

This paper reports on the design and optimization of current mirror MOSFET embedded pressure sensor. A current mirror circuit with an output current of 1 mA integrated with a pressure sensing n-channel MOSFET has been designed using standard 5 µm CMOS technology. The channel region of the pressure sensing MOSFET forms the flexible diaphragm as well as the strain sensing element. The piezoresistive effect in MOSFET has been exploited for the calculation of strain induced carrier mobility variation. The output transistor of the current mirror forms the active pressure sensing MOSFET which produces a change in its drain current as a result of altered channel mobility under externally applied pressure. COMSOL Multiphysics is utilized for the simulation of pressure sensing structure and Tspice is employed to evaluate the characteristics of the current mirror pressure sensing circuit. Simulation results show that the pressure sensor has a sensitivity of 10.01 mV/MPa. The sensing structure has been optimized through simulation for enhancing the sensor sensitivity to 276.65 mV/MPa. These CMOS-MEMS based pressure sensors integrated with signal processing circuitry on the same chip can be used for healthcare and biomedical applications.

Download Full-text

Three-Dimensional Arterial Pulse Signal Acquisition in Time Domain Using Flexible Pressure-Sensor Dense Arrays

Micromachines ◽

10.3390/mi12050569 ◽

2021 ◽

Vol 12 (5) ◽

pp. 569

Author(s):

Jianzhong Chen ◽

Ke Sun ◽

Rong Zheng ◽

Yi Sun ◽

Heng Yang ◽

...

Keyword(s):

Radial Artery ◽

Pressure Sensor ◽

Pulse Width ◽

Printed Circuit Boards ◽

Color Doppler ◽

Three Dimensional ◽

Pressure Sensors ◽

Sensor Arrays ◽

Signal Acquisition ◽

Dynamic Pulse

In this study, we developed a radial artery pulse acquisition system based on finger-worn dense pressure sensor arrays to enable three-dimensional pulse signals acquisition. The finger-worn dense pressure-sensor arrays were fabricated by packaging 18 ultra-small MEMS pressure sensors (0.4 mm × 0.4 mm × 0.2 mm each) with a pitch of 0.65 mm on flexible printed circuit boards. Pulse signals are measured and recorded simultaneously when traditional Chinese medicine practitioners wear the arrays on the fingers while palpating the radial pulse. Given that the pitches are much smaller than the diameter of the human radial artery, three-dimensional pulse envelope images can be measured with the system, as can the width and the dynamic width of the pulse signals. Furthermore, the array has an effective span of 11.6 mm—3–5 times the diameter of the radial artery—which enables easy and accurate positioning of the sensor array on the radial artery. This study also outlines proposed methods for measuring the pulse width and dynamic pulse width. The dynamic pulse widths of three volunteers were measured, and the dynamic pulse width measurements were consistent with those obtained by color Doppler ultrasound. The pulse wave velocity can also be measured with the system by measuring the pulse transit time between the pulse signals at the brachial and radial arteries using the finger-worn sensor arrays.

Download Full-text

Micromachined Pressure Sensors on Optical Fiber Tip

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.74.149 ◽

2009 ◽

Vol 74 ◽

pp. 149-152

Author(s):

X.M. Zhang ◽

M. Yu ◽

Silas Nesson ◽

H. Bae ◽

A. Christian ◽

...

Keyword(s):

Optical Fiber ◽

Pressure Sensor ◽

Linear Response ◽

Applied Pressure ◽

Pressure Sensors ◽

Outer Diameter ◽

Sensor Element ◽

Batch Fabrication ◽

In Vitro Measurements

This paper reports the development of a miniature pressure sensor on the optical fiber tip for in vitro measurements of rodent intradiscal pressure. The sensor element is biocompatible and can be fabricated by simple, batch-fabrication methods in a non-cleanroom environment with good device-to-device uniformity. The fabricated sensor element has an outer diameter of only 366 μm, which is small enough to be inserted into the rodent discs without disrupting the structure or altering the intradiscal pressures. In the calibration, the sensor element exhibits a linear response to the applied pressure over the range of 0 - 70 kPa, with a sensitivity of 0.0206 μm/kPa and a resolution of 0.17 kPa.

Download Full-text

Design and Simulation of Pressure Sensor for Ocean Depth Measurements

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.313-314.666 ◽

2013 ◽

Vol 313-314 ◽

pp. 666-670 ◽

Cited By ~ 5

Author(s):

K.J. Suja ◽

Bhanu Pratap Chaudhary ◽

Rama Komaragiri

Keyword(s):

Pressure Sensor ◽

Integrated Circuit ◽

Output Voltage ◽

Pressure Sensors ◽

Micro Electro Mechanical System ◽

Constant Thickness ◽

Piezoresistive Pressure Sensor ◽

Wide Pressure Range ◽

Processing Techniques ◽

Wide Pressure

MEMS (Micro Electro Mechanical System) are usually defined as highly miniaturized devices combining both electrical and mechanical components that are fabricated using integrated circuit batch processing techniques. Pressure sensors are usually manufactured using square or circular diaphragms of constant thickness in the order of few microns. In this work, a comparison between circular diaphragm and square diaphragm indicates that square diaphragm has better perspectives. A new method for designing diaphragm of the Piezoresistive pressure sensor for linearity over a wide pressure range (approximately double) is designed, simulated and compared with existing single diaphragm design with respect to diaphragm deflection and sensor output voltage.

Download Full-text

Study on the Stability of the Electrical Connection of High-Temperature Pressure Sensor Based on the Piezoresistive Effect of P-Type SiC

Micromachines ◽

10.3390/mi12020216 ◽

2021 ◽

Vol 12 (2) ◽

pp. 216

Author(s):

Yongwei Li ◽

Ting Liang ◽

Cheng Lei ◽

Qiang Li ◽

Zhiqiang Li ◽

...

Keyword(s):

High Temperature ◽

Pressure Sensor ◽

Pressure Sensors ◽

Extreme Environment ◽

Maximum Temperature ◽

Piezoresistive Effect ◽

Electrical Connection ◽

Contact Stability ◽

The Stability ◽

P Type

In this study, a preparation method for the high-temperature pressure sensor based on the piezoresistive effect of p-type SiC is presented. The varistor with a positive trapezoidal shape was designed and etched innovatively to improve the contact stability between the metal and SiC varistor. Additionally, the excellent ohmic contact was formed by annealing at 950 °C between Ni/Al/Ni/Au and p-type SiC with a doping concentration of 1018cm−3. The aging sensor was tested for varistors in the air of 25 °C–600 °C. The resistance value of the varistors initially decreased and then increased with the increase of temperature and reached the minimum at ~450 °C. It could be calculated that the varistors at ~100 °C exhibited the maximum temperature coefficient of resistance (TCR) of ~−0.35%/°C. The above results indicated that the sensor had a stable electrical connection in the air environment of ≤600 °C. Finally, the encapsulated sensor was subjected to pressure/depressure tests at room temperature. The test results revealed that the sensor output sensitivity was approximately 1.09 mV/V/bar, which is better than other SiC pressure sensors. This study has a great significance for the test of mechanical parameters under the extreme environment of 600 °C.

Download Full-text

Optimized Attachment to Achieve Different Buccolingual Movement of Maxillary Molars in Clear Aligner Orthodontic System: Biomechanical Analysis

Nanoscience and Nanotechnology Letters ◽

10.1166/nnl.2020.3151 ◽

2020 ◽

Vol 12 (11) ◽

pp. 1249-1254

Author(s):

Long Qin ◽

Qiao Wang ◽

Dongliang Zhang ◽

Xin He ◽

Binbin Wu

Keyword(s):

Tooth Movement ◽

Biomechanical Analysis ◽

Occlusal Surface ◽

Tooth Surface ◽

Force System ◽

Maxillary Molars ◽

Clear Aligner

The different positions and angles of attachment affecting the buccolingual movement of the maxillary molars, especially lingual tipping and negative torque movements, were biomechanically analyzed in order to determine how to better control and prevent unwanted movement of clear aligners. The aligner can be designed and placed appropriately to improve expected tooth movement. Based on mechanical principles, the force system of attachment was analyzed, and the optimum attachment position and angle for tipping and negative torque movement was determined. Attachment close to the enamel-cementum junction (ECJ) was found to achieve the best F (M/L) during negative torque movement; however, the angle should also be adjusted. Attachment close to the occlusal surface achieved greater tipping force at specific angles. When more tipping movement is required, it is recommended to place the attachment 3–5 mm from the ECJ. The angle of the attachment should be 110–120 degrees from the tooth surface. When place the attachment 4–5 mm from the ECJ, the angle of the attachment should be between 145 and 146.5 degrees.

Download Full-text

A Ceramic Diffusion Bonding Method for Passive LC High-Temperature Pressure Sensor

Sensors ◽

10.3390/s18082676 ◽

2018 ◽

Vol 18 (8) ◽

pp. 2676

Author(s):

Chen Li ◽

Boshan Sun ◽

Yanan Xue ◽

Jijun Xiong

Keyword(s):

High Temperature ◽

Pressure Sensor ◽

Pressure Sensors ◽

Alumina Ceramic ◽

Harsh Environments ◽

Ceramic Substrates ◽

Integrated Technology ◽

All Ceramic ◽

Test Platform ◽

Bonding Method

Alumina ceramic is a highly promising material for fabricating high-temperature pressure sensors. In this paper, a direct bonding method for fabricating a sensitive cavity with alumina ceramic is presented. Alumina ceramic substrates were bonded together to form a sensitive cavity for high-temperature pressure environments. The device can sense pressure parameters at high temperatures. To verify the sensitivity performance of the fabrication method in high-temperature environments, an inductor and capacitor were integrated on the ceramic substrate with the fabricated sensitive cavity to form a wireless passive LC pressure sensor with thick-film integrated technology. Finally, the fabricated sensor was tested using a system test platform. The experimental results show that the sensor can realize pressure measurements above 900 °C, confirming that the fabricated sensitive cavity has excellent sealing properties. Therefore, the direct bonding method can potentially be used for developing all-ceramic high-temperature pressure sensors for application in harsh environments.

Download Full-text