Bio-piezoelectricity: fundamentals and applications in tissue engineering and regenerative medicine.

In recent years, smart materials have piqued the interest of scientists and physicians in the biomedical community owing to their ability to modify their properties in response to an external stimulation or changes in their surroundings. Biocompatible piezoelectric materials are an interesting group of smart materials due to their ability to produce electrical charges without an external power source. Electric signals produced by piezoelectric scaffolds can renew and regenerate tissues through special pathways like that found in the extracellular matrix. This review summarizes the piezoelectric phenomenon, piezoelectric effects generated within biological tissues, piezoelectric biomaterials, and their applications in tissue engineering and their use as biosensors.

Design of Piezoelectric Heart Rate Monitoring Sensor for Wearable Applications

Having a good heart rate is important for a long lasting life and it is very important to monitor the heart rate of a person systematically. During this covid pandemic, it is highly necessary to monitor the pulse of a patient who is affected with covid. In order to keep track of the heart rate it is difficult to visit the hospital every time. Also, the available methods causes discomfort to the patients and these methods are very costly for a normal person. Piezoelectric pressure sensors are replacements for such highly expensive diagnosis systems. These sensors are easily accessible, have low cost and has high robustness. Since they give rapid responses to the input, it is widely used for medical, industrial and aerospace applications. This paper aims in designing and simulating a model of piezoelectric pressure sensor in COMSOL Multi physics platform satisfying the patients need of comfort and the figure of merits of pressure sensor. © 2022 IEEE.

Wearable Piezoelectric BioMEMS-based Sensor for SARS-CoV-2 (COVID-19) Virus Droplets Detection

Viral diagnostic is essential to the fields of medicine and bio-nanotechnology, but such analyses can present some complex analytical challenges. While molecular methods that are mostly used in clinical laboratories, for instance, reverse transcription-polymerase chain reaction (RT-PCR) and antigens tests require long acquisition times, and often provides unreliable results for COVID-19 virus detection, the piezo-based sensors coupled with MEMS have demonstrated a significant role in robust viral detection. In this work, we have designed and simulated a piezoelectric MEMS-based biosensor integrated into a wearable face mask for early detection of the SARS-CoV-2 virus droplets. We systematically investigated the influence of virus droplets in changing the applied stress on the cantilever receptor pit with change in mass when viruses (pathogens) from airborne coughing droplets-nuclei binds with coated antibodies on the sensor's cantilever layer with receptor pit thereby generating electric potential. Additionally, Bio-MEMS sensor results have manifested that it has the ability to detect a single size particle of 1 virion with a diameter ≥100 nm and mass of 1fg in a single cough containing droplet nuclei of radius 0.05μm in a less amount of time. Additionally, we empirically set electrical potential as thresholds parameter for our wearable biosensor embedded in the face mask for public monitoring to detect contagious virus particle droplets. Furthermore, this study presented the prospective use of MEMS-based sensing method to identify and detect other biological (bacteria and toxins) analytes. © 2021 IEEE.

Piezoelectricity Operated Automatic Door for Covid Safety

The COVID-19 pandemic also known as the Corona Virus worldwide epidemic is contemplate as the transcendent critical global health disaster in the world. Pneumonia, acute respiratory syndrome, and even death are the severity of this virus. We are living in a situation where Covid infection cases can be increased unexpectedly anytime if we do not follow the advisory of World Health organization (WHO). The majority of people who are infected with the virus has experienced mild to moderate fever. This virus spread rapidly in public places such as hospitals, metro station, railway station, malls etc. In such crowded areas, the chances of virus spread is high and we can prevent this by social distancing and measuring the temperature of the every individual without using human interference. In our idea we have introduced a fully automatic temperature detection system which would energized by piezoelectric generator. We have also implemented an automatic door opening system in which the door of a particular place will remain closed if temperature is above the preset value. The opening and closing of door is done through the piezoelectric generated power. © 2022 IEEE.

SARS-CoV-2 Infection-Of Music and Mechanics of Its Spikes! A Perspective.

The COVID-19 pandemic has been inflicted upon humanity by the SARS-CoV-2 virus, the latest insidious incarnation of the coronaviruses group. While in its wake intense scientific research has produced breakthrough vaccines and cures, there still exists an immediate need to further understand the origin, mechanobiology and biochemistry, and destiny of this virus so that future pandemics arising from similar coronaviruses may be contained more effectively. In this Perspective, we discuss the various evidential findings of virus propagation and connect them to respective underpinning cellular biomechanical states leading to corresponding manifestations of the viral activity. We further propose avenues to tackle the virus, including from a "musical" vantage point, and contain its relentless strides that are currently afflicting the global populace.

Potential of Piezoelectric Floor Tile for Harvesting Energy from Human Footsteps

Since the last decade, piezoelectric floor tile energy harvesters have been developed to convert wasted mechanical energy into usable electrical energy. Our team has also been developing and improving this kind of harvester, abbreviated as EHFT, for several years. One of the developmental problems was in reporting a realistic value of energy generated by EHFT because it depended heavily on many real-world factors. The objective of this study was to determine such realistic value by simulating those factors with a real-world traffic of 30 people entering a building. An EHFT together with proper electrical measurement devices were installed at the entrance of a building in King Mongkut's Institute of Technology, Thailand, and a group of 30 people were asked to step on it while entering the building. The value of the cumulative generated energy from the EHFT with those participants for a time duration of 600 s was found to be 450.26 mJ. This value was sufficiently high to constantly power a temperature sensor during a whole workday. Therefore, we are in the process of developing an automated Covid-19 detection station in which the temperature sensor will be powered by this EHFT. © 2021 IEEE.

A wearable exhaling-oxygen-sensing mask based on piezoelectric/gas-sensing coupling effect for real-time monitoring and uploading lung disease information

Comprehensive analysis of respiratory gases may provide noninvasive health monitoring of lung diseases, such as corona virus 2019 pneumonia. Here, a self-powered wearable mask has been fabricated for real-time monitoring and uploading exhaling oxygen information. Tetrapod ZnO (T-ZnO) nanostructures are hybridized with polyvinylidene fluoride (PVDF) that adhere to flexible fabric substrate on a mask. The piezoelectric effect of T-ZnO/PVDF is coupled with the gas sensing properties. The sensing unit can convert breath energy into piezoelectric signal without any external power supply, and the outputting piezoelectric voltage increases with increasing oxygen concentration, acting as the sensing signal. The sensing unit integrated with data processing module and wireless Bluetooth module can transmit the exhaling oxygen information to the mobile device, realizing real-time monitoring the oxygenation capacity of the lungs. This self-powered wearable approach can promote the lung diagnosis outside of clinical settings. © 2022 IOP Publishing Ltd.

Piezoelectric Nanofiber Membrane for Reusable, Stable, and Highly Functional Face Mask Filter with Long-Term Biodegradability

The emergence of the SARS-CoV-2 pandemic and airborne particulate matter (PM) pollution has led to remarkably high demand for face masks. However, conventional respirators are intended for single use and made from nondegradable materials, causing serious concern for a plastic-waste environmental crisis. Furthermore, these facemasks are weakened in humid conditions and difficult to decontaminate. Herein, a reusable, self-sustaining, highly effective, and humidity-resistant air filtration membrane with excellent particle-removal efficiency is reported, based on highly controllable and stable piezoelectric electrospun poly (l-lactic acid) (PLLA) nanofibers. The PLLA filter possesses a high filtration efficiency (>99% for PM 2.5 and >91% for PM 1.0) while providing a favorable pressure drop (≈91 Pa at normal breathing rate) for human breathing due to the piezoelectric charge naturally activated by respiration through the mask. The filter has a long, stable filtration performance and good humidity resistance, demonstrated by a minimal declination in the filtration performance of the nanofiber membrane after moisture exposure. The PLLA filter is reusable via common sterilization tools (i.e., an ultrasonic cleaning bath, autoclave, or microwave). Moreover, a prototype of a completely biodegradable PLLA nanofiber-based facemask is fabricated and shown to decompose within 5 weeks in an accelerated degradation environment. © 2022 Wiley-VCH GmbH

Gas Sensor Based on Biohydroxyapatite to Study the Volatile Compounds of Nasal Secretion

The paper investigates the properties of gas sensors based on biohydroxyapatite for diagnostic the state of the upper respiratory tract of calves and humans. The process of synthesis of biohydroxyapatite of different mass is described. The peculiarities of sorption of volatile compounds on this sorbent depending on mass are considered for two modes of measurement (injection and frontal). The effectiveness and selectiveness of organic vapor microweighting using biohydroxyapatite phases of different mass are estimated. Possibilities of volatile organic compounds vapors identification in a mixture without separation are considered. For this task, the new parameters are calculated by the signals of one or two piezoelectric sensors with biohydroxyapatite of different masses. Results of analysis and identification of substances in the gas phase over nasal secretions of calves and humans with various respiratory diseases are presented. The intervals of the values of the calculated parameters are determined for reliable selection of samples into the "inflammation" group. The first and second order errors have been estimated in binary classification into groups "healthy" and "inflammation". The minimum number of false-positive responses in the classification of samples is achieved using the parameters of two sensors with a biohydroxyapatite of different masses.

Available Technologies and Commercial Devices to Harvest Energy by Human Trampling in Smart Flooring Systems: A Review

Technological innovation has increased the global demand for electrical power and energy. Accordingly, energy harvesting has become a research area of primary interest for the scientific community and companies because it constitutes a sustainable way to collect energy from various sources. In particular, kinetic energy generated from human walking or vehicle movements on smart energy floors represents a promising research topic. This paper aims to analyze the state-of-art of smart energy harvesting floors to determine the best solution to feed a lighting system and charging columns. In particular, the fundamentals of the main harvesting mechanisms applicable in this field (i.e., piezoelectric, electromagnetic, triboelectric, and relative hybrids) are discussed. Moreover, an overview of scientific works related to energy harvesting floors is presented, focusing on the architectures of the developed tiles, the transduction mechanism, and the output performances. Finally, a survey of the commercial energy harvesting floors proposed by companies and startups is reported. From the carried-out analysis, we concluded that the piezoelectric transduction mechanism represents the optimal solution for designing smart energy floors, given their compactness, high efficiency, and absence of moving parts.

An ultra-low-cost electroporator with microneedle electrodes (ePatch) for SARS-CoV-2 vaccination.

Vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other pathogens with pandemic potential requires safe, protective, inexpensive, and easily accessible vaccines that can be developed and manufactured rapidly at a large scale. DNA vaccines can achieve these criteria, but induction of strong immune responses has often required bulky, expensive electroporation devices. Here, we report an ultra-low-cost (<1 USD), handheld (<50 g) electroporation system utilizing a microneedle electrode array ("ePatch") for DNA vaccination against SARS-CoV-2. The low cost and small size are achieved by combining a thumb-operated piezoelectric pulser derived from a common household stove lighter that emits microsecond, bipolar, oscillatory electric pulses and a microneedle electrode array that targets delivery of high electric field strength pulses to the skin's epidermis. Antibody responses against SARS-CoV-2 induced by this electroporation system in mice were strong and enabled at least 10-fold dose sparing compared to conventional intramuscular or intradermal injection of the DNA vaccine. Vaccination was well tolerated with mild, transient effects on the skin. This ePatch system is easily portable, without any battery or other power source supply, offering an attractive, inexpensive approach for rapid and accessible DNA vaccination to combat COVID-19, as well as other epidemics.

A Prototype Sensor System Using Fabricated Piezoelectric Braided Cord for Work-Environment Measurement during Work from Home.

We proposed a new prototype sensor system to understand the workload of employees during telework. The goal of sensing using such a system is to index the degree of stress experienced by employees during work and recognize how to improve their work environment. Currently, to realize this, image processing technology with a Web camera is generally used for vital sign sensing. However, it creates a sense of discomfort at work because of a strong sense of surveillance. To truly evaluate a working environment, it is necessary that an employee be unaware of the sensor system and for the system to be as unobtrusive as possible. To overcome these practical barriers, we have developed a new removable piezoelectric sensor incorporated in a piezoelectric poly-L-lactic acid (PLLA) braided cord. This cord is soft and flexible, and it does not cause any discomfort when attached to the cushion cover sheet. Thus, it was possible to measure the workload of an employee working from home without the employee being aware of the presence of a sensor. Additionally, we developed a system for storing data in a cloud system. We succeeded in acquiring continuous long-term data on the vital signs of employees during telework using this system. The analysis of the data revealed a strong correlation between behavior and stress.