Piezo Buzzer Research Articles

INVESTIGATION OF LOW-COST PIEZOELECTRIC FORCE SENSOR

The use of piezoelectric force sensors is well-established in industrial systems and devices, but their adoption in consumer products has been limited due to the high cost of implementation as well as complex peripheral electronics. This paper proposes an alternative approach to force sensing using commonly available piezoelectric buzzer elements, which could potentially reduce the cost of such sensors and promote their integration into consumer products. The paper represents experimental investigations of output characteristics of two different piezoelectric force sensors, which are based on disc-shaped buzzers. The goal of the investigation is to indicate and experimentally confirm electromechanical characteristics of proposed piezoelectric sensors under different sensing and signal management conditions. The results of the investigations showed that piezo buzzers have the potential to serve as cost-effective force sensors in consumer products as well as in different mechatronic systems.

SOS Device for Women Safety

Women security is need of the hour now-a-days. In India, there are many cases of women harassment and molestation. Safety of women matters let be whether at home, outdoor or it be their work place. The literature surveyed shows that there are many mobile applications that are used for women safety purpose. One recent research study shows that there is a footwear chip which is sticked to the footwear that gets activated when the person taps one leg behind the other 4 times. We focus on developing a prototype that is a smart sos device which gets activated by pressing the button either once or twice. The GPS location is sent to the ICE contacts as soon as the device is turned on. The victim's current location is sent to the ICE contacts. Double press activates device turning on, a Piezo buzzer siren will go out. The buzzer's volume ranges from 80 to 110 dB, and it may be heard 50 feet away. Until the device is turned off it will send the location on the interval of 5 mins and will keep on beeping continuously.

Design and Evaluation of a Wearable Biofeedback Training System to Reduce Trip-Related Falls During Level Walking

Trip-related falls are a major concern especially for older adults and individuals with gait impairments as they can lead to serious injuries, hospitalizations and negatively impact the quality of life. A low Minimum Toe Clearance (MTC) can be a predictor of tripping risk and thus, increasing the MTC is a possible way to reduce trip-related falls. In this paper, a wearable system is proposed that can measure the MTC in real-time using two Time-of-Flight (ToF) sensors on the shoe and provide auditory biofeedback using a piezo buzzer. Ten healthy female adults were recruited to walk in four conditions: baseline, biofeedback, short retention (same day), and long retention (next day) to design and validate our gait training tool. Average MTC values were compared pre-feedback, post-feedback, and post-retention, and our analysis revealed significant differences between the feedback and retention sessions for the training system. Therefore, the proposed system has the potential to be used as a wearable training system to minimize tripping risks in older adults and gait-impaired populations.

Laser Based Smart Security Apparatus Using Arduino

Abstract: Our paper deals with the plan and execution of a LASER based smart security system for discovering burglar. The principal edge of using the Laser system is that the burglar is unmindful of the fact that a security system is fix in the entry points like doors and windows since laser rays can travel long distances and are almost imperceptible. When someone go through the laser ray the circuit senses the cutoff and stumble the alarm. The alarming sound does not stop until someone turns it off manually after scrutnizing. It is one of the most economical security apparatus that can be used for indoors as well as outdoors. This apparatus centre of attention is on sending a photo of the burglar into the registered email address for sustainable verification with the help of LDR and WIFI module. It is quite competent and need very minimal power. Important terms: Arduino, LDR module, WIFI module, Piezo buzzer, message alert, laser module security

Do You Hear What I Hear: The Balancing Act of Designing an Electronic Hockey Puck for Playing Hockey Non-Visually

Blind hockey is a sport that is gaining popularity in the United States after having an international presence for years. In blind hockey, a modified puck is used that emits sounds via ball bearings that rattle inside the puck when it is moving. The modified puck’s lifetime is minimal due to its lack of durability, and it does not provide feedback when the puck stops moving. This article presents an evaluation of multiple prototypes that investigate the appropriate acoustic profiles for an electronic version of a puck that has the ability to overcome some of these challenges. Our approach leverages the use of alternative 3D printable materials and the implementation of four distinct sound profiles: the league-standard puck in blind hockey, a 3.5kHz piezo buzzer, an 800Hz sine tone, and simulated white noise. We present the design and prototype of the pucks, along with benchtop and user validation tests of the prototypes, comparing them to the league standard puck with a focus on acoustic performance. Participants rated the white noise sound profile highest in pleasantness and loudness and the LSP highest in localization. The white noise sound profile was associated with lower angle and distance errors. Of the prototypes produced, the white noise prototype puck appeared to demonstrate the most promise for playing hockey non-visually. We close with a discussion of recommendations for future electronic hockey puck designs to support blind hockey moving forward.

Coupled field analysis of piezoelectric materials for sensor and actuator applications using finite element method

Sensors and actuators made of materials whose characteristics may be modified by external parameters have a wide range of uses. Piezoelectric materials come under this category that can convert mechanical energy to electrical energy and vice versa. In our daily lives, we come across a piezoelectric effect whether we realize it or not. To name a few are the piezo igniters for cooking, ultrasonic parking sensors, piezo buzzers in alarm clocks, and mobile phones. Any device can be modeled analytically in order to predict its behavior based on the fundamental theory that drives it. For the modeling of ultrasonic devices, the finite element approach is commonly employed, and commercial software are available. ANSYS' coupled field analysis allows you to evaluate the interaction between two fields. Static, modal, harmonic, and transient analyses are possible with regard to piezoelectric analysis. This paper presents the modal analysis of piezoelectric structures that enables the determination of the natural frequencies and mode shapes of the structure. The natural frequency thus obtained is verified with harmonic analysis.

Rotational multi-beam energy harvester with up-conversion mechanism in an extremely low frequency scenario

We propose a novel frequency-up converting device in an extremely low frequency rotating scenario based on a multi-beam piezoelectric energy harvester and multiple impacts. The rotating multi-beam structure consists of a piezoelectric sheet added to a top beam, a large seismic mass added to a bottom beam and an elastic stop which can be eventually replaced by a buzzer. At half of the rotating cycle, the bottom beam impacts the top beam by means of a spring generating energy by a frequency up-conversion mechanism. At the other half of the cycle, the up and bottom beam separate from each other and the bottom beam impacts an elastic stop or a buzzer which are used to simultaneously recover the kinetic energy of the collision, generate energy (buzzer) and prevent possible damage to the structure. An analytical model that governs the electromechanical equations and the impact dynamics is proposed to provide a means to predict the generated output energy. The model is based on the Euler-Bernoulli structural theory for the beams and a piezoelectric nonlinear constitutive model. Two different energy generation possibilities are studied, depending on the selection of the elastic stop or the buzzer. When the elastic spring acts as stop, the collision between the bottom beam and the stop is more elastic. Replacing the spring stop with a piezo buzzer adds to the system an additional mechanism of energy conversion. By making several experimental tests, the analytical model is validated by computing the cumulated energy. The results demonstrate that the buzzer element significantly improves the harvested power when it replaces the elastic stop. To estimate the usable power of the device, rectifier circuits coupled to the piezo elements are built and test. The results show that in the case of the buzzer used as a stop, a rectified power that overcomes 6.4 times in average other previous designs is harvested in the range of 0.8–2.2 Hz over an electrical load of 10 kΩ. The amount of collected power is suitable for autonomous sensing of wind turbines of 30 kW with rotational speeds of between 50 and 150 rpm.

Applications of Piezoelectricity: Home safety device

The following piezoelectric security doormat is a safety device based on the piezoelectric effect and its converse. Pressure exerted by the person on the doormat is detected by the piezoelectric plates lined inside the mat. These piezoelectric plates are connected in a parallel orientation to make the doormat more durable because if a single piezoelectric plate becomes dysfunctional, the remaining branches will still work and keep the entire system operational. Once the pressure is detected, an electric charge is generated due to the piezoelectric effect. This electric charge is sensed by the Arduino. The coding of the Arduino is done in such a way that whenever it senses an electrical input, the piezo buzzer attached to it is turned on. This piezoelectric buzzer works on the principle of inverse piezoelectric effect where the voltage difference applied induces mechanical stress on the plates producing vibrations. Thus, the security doormat on sensing pressure difference whenever someone stands on it turns on the buzzer connected to it and therefore, alerts the residents.

Exploring the cantilever: teaching tools for atomic force microscopy

This paper presents a series of experiments that aim to aid with the understanding of some of the fundamental concepts pertaining to the resonance of cantilevers. The goal is to provide an accessible platform for exploring how the cantilever, one of the fundamental components in non-contact scanning probe/atomic force microscopy, is utilized in measuring forces. A straightforward experiment that utilizes a piezo buzzer and oscilloscope to measure the natural resonance frequency of a cantilever is showcased. This information is used to demonstrate how the frequency is related to the length and to extract information about the Young’s modulus of the material. It also presents how one is able to utilize a piezo-driven craft stick to measure masses within a 100th of a gram. Utilizing the same driven craft sticks, are a series of experiments exhibited that employ the use of a magnetic probe to explore the differences between attractive and repulsive forces. In addition, a discussion of how these results relate to the tip-sample interactions in atomic force microscopy will be displayed. The experiments presented were developed as part of an undergraduate modern physics laboratory and a scanning probe microscopy course. A review of how these experiments were implemented in these courses will be presented. The experiments highlighted in this manuscript were employed as part of a distance learning kit for a modern laboratory, that was converted to an e-learning classroom due to social distancing restrictions. A description of the kits utilized will be provided.

Liquefied petroleum gas monitoring and leakage detection system using nodemcu ESP8266 and wi-fi technology

<span>Liquefied Petroleum Gas which is popularly known as LPG is a clean source of energy which is highly flammable and usually compressed into storage tanks. Due to the flammable nature of LPG it can easily lead to uncontrollable explosions in the presence of any ignition action or may lead to complete depletion of oxygen in a particular area. This study is focused on the fabrication of a system that would detect, monitor and control LPG gas leakages for domestic gas cylinders. A MQ-2 gas sensor was used for the detection of LPG gas leakages, the monitoring aspect was satisfied locally through notifications triggered by LEDs, piezo buzzer and remotely through the use of an application known as Blynk. The control aspect was implemented with the use of a stepper motor which turns off gas cylinder regulators whenever gas concentrations are high. All operations are primary hinged on the NodeMCU ESP8266 controller and Wi-Fi communication technology. </span>

Design of an Integrated Anti-Hardening System for Carbon-In-Leach Tanks

Slurry density monitoring is of paramount importance in the industrial world. Most industries, especially cement and mineral processing industries, employ this method to obtain good quality products. However, most Carbon-In-Leach (CIL) tanks of gold processing industries do not use slurry density monitoring systems. As a result, many a time, agitation difficulties occur when the slurry begins to harden. This paper, therefore, seeks to design an integrated anti-hardening system for CIL tanks, with the aid of a microcontroller, to monitor the density of the slurry in order to prevent it from hardening. Slurry density measurement was achieved with the help of a strain gauge pressure sensor and a couple of level sensors. Atmega 328p microcontroller board was programmed to continuously compute the density of the slurry from values of pressure and level of slurry in the tank indicated by the pressure and level sensors, respectively. The microcontroller responds to slurry hardening by activating a light emitting diode and triggering the piezo buzzer when a set point is reached. The designed circuit was successfully simulated using Proteus 8.2 design suite software to ascertain its functionality. Based on the results obtained, the light emitting diode and piezo buzzer activated when the set point was reached. It was concluded that the anti-hardening system is effective for constantly monitoring the density of the slurry to prevent it from hardening. It was also recommended that the mining industries could employ the designed system to monitor the density in order to prevent hardening of slurry in CIL tanks. Keywords: Carbon-In-Leach Tanks, Slurry Densisty, Strain Guage Pressure Sensor, Microcontroller

Sensor based on piezo buzzers for simultaneous measurement of fluid viscosity and density

A novel low cost sensor is proposed to measure simultaneously viscosity and density of Newtonian fluids. In the proposed configuration, the sensor is built with two piezoelectric buzzers disks. One disk is excited with a step signal while the other is used to read the sensor response. Damping factor and resonant frequencies are measured when the sensor is immersed in fluids of different densities and viscosities. Excitation signal and data acquisitions are phase locked, therefore ensemble averaging techniques are employed to improve signal to noise ratio. Binary mixtures of glycerol and ethanol are selected for assessment of sensor capabilities. Due to the high temperature dependency of fluid viscosities a parametric variation of the fluid properties could be achieved by varying the fluid temperature. Dynamic response of the sensor is calibrated against the fluid properties for viscosities up to 200 cP and densities up to 1.23 g/cm3. Estimated uncertainties are ±8 cP and ±0.03gm/cm3, with 95% of confidence, for viscosity and specific gravity, respectively. These uncertainties include sensor sensitivity to temperature. Results are promising and show a proof of concept. Thus, disposable and very low cost devices can be developed based on the proposed sensor.

A tunable acoustic metamaterial based on piezo buzzers and passive circuits

The limitation of current acoustic metamaterials with fixed properties or working at fixed frequency ranges once they are fabricated promotes the investigation of tunable metamaterials. Here, we propose a tunable acoustic metamaterial consisting of piezo buzzers and passive circuits. An analytic approach is developed to analyze the acoustic characteristics. Results show that the exterior passive circuit can induce a band gap at wavelengths much larger than the structure size. In this gap, the structure behaves as an effective medium with positive density and negative elastic modulus. Our work provides a feasible and simple approach to design adjustable acoustic filters or insulators.

Note: A 3D-printed flexure nanostage driven by piezo buzzers.

A flexure nanostage capable of being manufactured at home at a low cost is proposed. A prototype of the said stage-fabricated using a three-dimensional (3D) printer-exhibited single degree-of-freedom motion. Limitations with regard to material, fabrication precision, and actuator force were overcome, and cross talk was reduced by designing flexure holes. Fabrication of such holes was exclusively facilitated by the use of 3D-printing technology. Experimental results demonstrate that the proposed stage can perform linear motion over a 10-μm distance over a voltage range of 30 V.

Implementation of Intelligent Automated Gate System with QR Code

This paper is about QR code-based automated gate system. The aim of the research is to develop and implement a type of medium-level security gate system especially for small companies that cannot afford to install high-tech auto gate system. IAGS is a system that uses valid staffs’ QR code pass card to activate the gate without triggering the alarm. It is developed to connect to the internet and provide a real-time email notification if any unauthorized activities detected. Besides that, it is also designed to record all the incoming and outgoing activities for all staff. All QR code pass cards that are generated to staff will be encrypted to provide integrity to the data. The system is based on items such as PIR motion sensor, servo motor, Arduino microcontroller, Piezo buzzer, and camera. The software is implemented using VB.NET and the QR recognition level is about 99% accurate.

Frequency tuning allows flow direction control in microfluidic networks with passive features.

Frequency tuning has emerged as an attractive alternative to conventional pumping techniques in microfluidics. Oscillating (AC) flow driven through a passive valve can be rectified to create steady (DC) flow, and tuning the excitation frequency to the characteristic (resonance) frequency of the underlying microfluidic network allows control of flow magnitude using simple hardware, such as an on-chip piezo buzzer. In this paper, we report that frequency tuning can also be used to control the direction (forward or backward) of the rectified DC flow in a single device. Initially, we observed that certain devices provided DC flow in the "forward" direction expected from previous work with a similar valve geometry, and the maximum DC flow occurred at the same frequency as a prominent peak in the AC flow magnitude, as expected. However, devices of a slightly different geometry provided the DC flow in the opposite direction and at a frequency well below the peak AC flow. Using an equivalent electrical circuit model, we found that the "forward" DC flow occurred at the series resonance frequency (with large AC flow peak), while the "backward" DC flow occurred at a less obvious parallel resonance (a valley in AC flow magnitude). We also observed that the DC flow occurred only when there was a measurable differential in the AC flow magnitude across the valve, and the DC flow direction was from the channel with large AC flow magnitude to that with small AC flow magnitude. Using these observations and the AC flow predictions from the equivalent circuit model, we designed a device with an AC flowrate frequency profile that was expected to allow the DC flow in opposite directions at two distinct frequencies. The fabricated device showed the expected flow reversal at the expected frequencies. This approach expands the flow control toolkit to include both magnitude and direction control in frequency-tuned microfluidic pumps. The work also raises interesting questions about the origin of flow reversal behavior that may be addressed by the further study of the circuit model behavior or dynamic modeling of the fluid-solid mechanics of the valve under the AC flow.

Simple unimorph deformable mirrors fabricated from piezo buzzers

This study shows how unimorph deformable mirrors can be effectively fabricated out of commercially available piezo-buzzers without any high-tech equipment. Our design involves a quad-channel mirror with monolithically integrated flexures. The mirror is controlled by a custom quad-channel high-voltage driver unit, capable of 93 Vp-p and 75 kpps performance. The system exhibits 16-bit resolution over the angular working range of ±1.85 mrad, with 0.04 mrad V−1 angular sensitivity and 14% hysteresis. We demonstrate the mirror performance for focus control in microscopy and high-precision laser beam steering, opening a wide variety of applications in computational imaging, confocal microscopy, optical tweezing and laser lithography.

Design of magnetic field alarm powered by magnetic energy harvesting

Abstract This paper presents a design of magnetic field alarm powered by magnetic energy harvesting. It consists of an energy harvesting module, Cockcroft-walton circuit and piezo buzzer. The energy harvesting module is composed of coil and magnetic flux concentration core. It can generate 200 μW from an environmental magnetic field of 200 μT at 60 Hz. The Cockcroft-walton circuit can converts the ac voltage to a suitable dc voltage for the piezo buzzer. This alarm can notice not only the magnetic field level defined by ICNIRP2010 but also the existence of magnetic field energy to be harvested. It is the first demonstration of a “self-generating component” powered by magnetic energy harvesting.

Diaphorina citri(Hemiptera: Liviidae) Responses to Microcontroller-Buzzer Communication Signals of Potential Use in Vibration Traps

Monitoring of Diaphorina citri Kuwayama (Hemiptera: Liviidae) populations is an important component of efforts to reduce damage caused by huanglongbing, a devastating disease it vectors in citrus groves. Currently, D. citri is monitored primarily by unbaited sticky traps or visual inspection of trees. A potentially more effective method might result from attracting males to vibrational communications produced by females. Males call with wing-buzzing substrate-borne vibrations while searching for females on tree branches and stems. When nearby receptive females detect the calls, they reply immediately in synchronized duets that help direct the males towards them. The spectral and temporal patterns of the duets have been analyzed in previous studies and have been mimicked successfully with computer-operated vibration exciters. Males and females both respond to signals produced by either sex but display different behaviors during duets. To devise practical methods to attract and trap males with vibrational signals in field environments, a microcontroller platform was tested for capability to control inexpensive vibration sensing and output devices. The microcontroller was programmed to send mimics of different D. citri signals to a piezo buzzer for substrateborne broadcast. A mimic that elicited strong female responses was tested in bioassays that jointly compared it with other previously bioassayed signals, and the response to the mimic was found to be statistically comparable to that elicited by a recorded male call. The successful result suggests there is opportunity to develop microcontroller systems further as a means of trapping psyllids.

유니몰프 압전소자를 이용한 발전 판넬의 출력특성에 관한 연구

The ability for energy harvesting via the piezoelectric effect was studied for a unimorph element such as piezo buzzer. A simple equivalent circuit was proposed to predict the energy generated based on the internal stress. Unimorphs with a metal-cavity were used as a driving device of the generation panel. Both the AC open voltage and DC output voltage as a function of pressure period and number of element were measured. For the unimorph generation circuit, DC output voltage varies with pressure period, reaching a maximum value at <TEX>$470{\mu}F$</TEX>. The maximum output voltage a according to load resistance was measured at <TEX>$1M{\Omega}$</TEX>. Data analysis of the DC output voltage and time constant indicated that number of piezoelectric element of optimum was 60~80. It was found that piezoelectric unimorph has the possibility to be used as the driving element of the electric generation.