Biomedical Applications of Perovskites: The Era of Bio Piezoelectric Systems E-Book
Ankush Chauhan
63,99 €
Mehr erfahren.
- Herausgeber: Bentham Science Publishers
- Kategorie: Fachliteratur
- Sprache: Englisch
Biomedical Applications of Perovskites: The Era of Bio-Piezoelectric Systems focuses on recent developments in the area of piezoelectric systems and their biomedical applications. A compilation of 19 edited chapters covers different piezoelectric materials, device designs, and their use cases. Readers will be familiarized with the many perovskite materials being used in research and development as well as the role they play in designing novel medical devices and biomaterials. Key Features - systematically explains the piezoelectric perovskite materials starting from their introduction, their structure and synthesis techniques - explains the key materials used in devices such as pacemakers and nanogenerators - highlights a range of applications including bone regeneration and growth, bone replacement, tissue engineering, dental science, neurotrauma and neurodegenerative disease treatment and bionic prosthesis - discusses future challenges and the roadmap for piezoelectric perovskite materials - Presents scientific references for advanced reading Readership Researchers, professionals and students in biomedical engineering programs; Science readers who want to learn about perovskites and associated devices in-depth.
Das E-Book können Sie in Legimi-Apps oder einer beliebigen App lesen, die das folgende Format unterstützen:
Seitenzahl: 686
Veröffentlichungsjahr: 2024
Ähnliche
BENTHAM SCIENCE PUBLISHERS LTD.
End User License Agreement (for non-institutional, personal use)
This is an agreement between you and Bentham Science Publishers Ltd. Please read this License Agreement carefully before using the book/echapter/ejournal (“Work”). Your use of the Work constitutes your agreement to the terms and conditions set forth in this License Agreement. If you do not agree to these terms and conditions then you should not use the Work.
Bentham Science Publishers agrees to grant you a non-exclusive, non-transferable limited license to use the Work subject to and in accordance with the following terms and conditions. This License Agreement is for non-library, personal use only. For a library / institutional / multi user license in respect of the Work, please contact: [email protected].
Usage Rules:
All rights reserved: The Work is the subject of copyright and Bentham Science Publishers either owns the Work (and the copyright in it) or is licensed to distribute the Work. You shall not copy, reproduce, modify, remove, delete, augment, add to, publish, transmit, sell, resell, create derivative works from, or in any way exploit the Work or make the Work available for others to do any of the same, in any form or by any means, in whole or in part, in each case without the prior written permission of Bentham Science Publishers, unless stated otherwise in this License Agreement.You may download a copy of the Work on one occasion to one personal computer (including tablet, laptop, desktop, or other such devices). You may make one back-up copy of the Work to avoid losing it.The unauthorised use or distribution of copyrighted or other proprietary content is illegal and could subject you to liability for substantial money damages. You will be liable for any damage resulting from your misuse of the Work or any violation of this License Agreement, including any infringement by you of copyrights or proprietary rights.Disclaimer:
Bentham Science Publishers does not guarantee that the information in the Work is error-free, or warrant that it will meet your requirements or that access to the Work will be uninterrupted or error-free. The Work is provided "as is" without warranty of any kind, either express or implied or statutory, including, without limitation, implied warranties of merchantability and fitness for a particular purpose. The entire risk as to the results and performance of the Work is assumed by you. No responsibility is assumed by Bentham Science Publishers, its staff, editors and/or authors for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products instruction, advertisements or ideas contained in the Work.
Limitation of Liability:
In no event will Bentham Science Publishers, its staff, editors and/or authors, be liable for any damages, including, without limitation, special, incidental and/or consequential damages and/or damages for lost data and/or profits arising out of (whether directly or indirectly) the use or inability to use the Work. The entire liability of Bentham Science Publishers shall be limited to the amount actually paid by you for the Work.
General:
Any dispute or claim arising out of or in connection with this License Agreement or the Work (including non-contractual disputes or claims) will be governed by and construed in accordance with the laws of Singapore. Each party agrees that the courts of the state of Singapore shall have exclusive jurisdiction to settle any dispute or claim arising out of or in connection with this License Agreement or the Work (including non-contractual disputes or claims).Your rights under this License Agreement will automatically terminate without notice and without the need for a court order if at any point you breach any terms of this License Agreement. In no event will any delay or failure by Bentham Science Publishers in enforcing your compliance with this License Agreement constitute a waiver of any of its rights.You acknowledge that you have read this License Agreement, and agree to be bound by its terms and conditions. To the extent that any other terms and conditions presented on any website of Bentham Science Publishers conflict with, or are inconsistent with, the terms and conditions set out in this License Agreement, you acknowledge that the terms and conditions set out in this License Agreement shall prevail.Bentham Science Publishers Pte. Ltd. 80 Robinson Road #02-00 Singapore 068898 Singapore Email: [email protected]
PREFACE
In the present era, self-powered technology and smart materials have paved the way for the design of several biomedical applications. Piezoelectric is a class of materials that could generate an electrical output on the application of strain or stress. Perovskite compositions are the best-known and the largest group of ferroelectric and piezoelectric materials. The book “Biomedical Applications of Perovskites: The Era of Bio-Piezoelectric Systems” focuses on the recent progress made in the area of piezoelectric systems and their applications. More specifically, this book focuses on various piezoelectric materials, device designs, and possible applications in the field of medical science. The future challenges and the roadmap for piezoelectric perovskite materials are discussed in this book. This book systematically explains the piezoelectric perovskite materials, starting from their introduction, their structure, synthesis techniques and their applications in the field of medical science, where the uses of piezoelectric perovskites have been discussed in different chapters.
This book explains the key devices, such as pacemakers, nanogenerators, etc, that are made up of perovskite materials. The biocompatibility of perovskite materials has also been discussed along with the cell response of these materials. This book also explains the applications of perovskite materials in bone regeneration and growth, bone replacement, tissue engineering, dental science, neurotrauma and neurodegenerative treatment and bionic prostheses in the form of various chapters. Herein, the issues that the biomedical industry is facing in terms of perovskite materials are also discussed. Thus, through this book, every possible application of the perovskite materials has been discussed.
This is a kind of unique book because in this book various experts of the related field have shared their expert opinion in the form of chapters. Each chapter is unique and provides insightful information so that researchers can innovate in a particular field and provide a better solution. Each chapter is a hot topic of research, and using the information in this book, one can pursue research for the development of new materials for the biomedical industry.
Editors would like to thank each of the authors for their valuable contributions to the book.
List of Contributors
Introduction to Piezoelectric Perovskites
Neetu Dhanda1,Preeti Thakur2,*,Atul Thakur2Abstract
Perovskite (Calcium titanium oxide), which was discovered in 1839 by Perovski, a Russian mineralogist, has some favorable photophysical characteristics that enable perovskite and its nanocrystals to be used in the field of biomedical research. Presently, perovskites are being explored for various medical applications, including X-ray detection and imaging, cancer treatment, orthopedic implants and as antimicrobial agents. Advancements in nanocrystal research allowed the exploration of perovskites for their antibacterial, antifungal and antiviral activity against Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2). The antibacterial activity of several perovskite nanoparticles was explored, and to mention a few, Cesium lead bromide and zinc oxide perovskite nanoparticles showed activity against Escherichia coli, while Lanthanum potassium ferrate and silver-based perovskites against Staphylococcus aureus and Pseudomonas aeruginosa. This chapter will review the potential research studies that explored the anti-microbial activity of perovskites and their nanoparticles against bacteria, viruses, fungi and other microorganisms and provide insight into the mechanisms by which these particles exert antimicrobial action. Further, this chapter will discuss the potential biomedical applications of the antimicrobial activity of perovskites.
1. INTRODUCTION
1.1. Piezoelectricity
Piezoelectric materials have the capacity to produce a potential (electric) in reaction to a mechanical movement or piezoelectric effect (direct) in response to an inverse piezoelectric effect (Fig. 1). Many applications have made use of this class of smart materials, mainly in the fields of communications and information,
industrial automation, and medical diagnosis, etc. Transducers, sensors, actuators, imaging devices, ultrasonic motors, nano-positioners, and other similar devices are examples of typical uses. The brothers Pierre Curie and Jacques made the initial finding of the piezoelectric effect in 1880 [1, 2]. These creative forerunners discovered that certain crystals (inorganic), like quartz, tourmaline, Rochelle salt, topaz, and sugarcane, accumulated an electrical charge when mechanical stress was applied and that the voltage generated by the material was proportional to the mechanical stress. The direct piezoelectric effect (Fig. 1(a)) is the phenomenon that connects strain (mechanical action) to an electrical reaction (displacement, polarization, or electric field). Afterward, the piezoelectric effect (inverse) was also verified experimentally through observations made of acentric symmetry in single crystals (Fig. 1(b)), where an external field (electric) caused the crystal to mechanically respond by causing strain or stress in the sample.
Fig. (1)) (a) The direct piezoelectric effect, and (b )inverse piezoelectric effect.2. PIEZOELECTRIC MATERIALS
The sonar detector, which was produced initially in the 1st World War, was the first significant piezoelectric device application. P. Langevin and his colleagues started developing a submarine detector (ultrasonic) in 1917. The hydrophone detector was used to listen for audio echoes, and a thin quartz transducer expertly bonded among two steel plates (whose resonance frequency was around 50 kHz). The gadget was housed in a casing made to withstand immersion in salt water [3]. After the war, they kept working toward their objective, which was to use a transducer to create a sound pulse of high-frequency and then how long it took for the pulse to bounce off a submerged item. With this knowledge, it was possible to determine how far away the submerged object was from the pulse's origin. Since the success of this effort had sparked broad interest in piezoelectric devices and materials, none of the industrial nations had ignored the strategic significance of their accomplishment. New piezoelectric components, tools, and applications were created and used during the ensuing decades. There are multiple applications of perovskites in the electronic industry, such as detectors, actuators, inkjet, Quantum dot Light Emitting Diodes, etc. [4-6].
It was discovered by inaccessible research teams in the USSR, Japan, and US during World War II that some ceramic materials made by sintering metallic oxide powders had dielectric constants (r) that were up to 100 times larger than those of ordinary quartz crystals. Ferroelectrics are a new class of artificial ceramic materials that have piezoelectric (d33) constants that are significantly greater than those of natural materials [3]. Ferroelectrics show similar behavior as that of ferromagnetism in magnetic materials [7]. Due to this development, there is now a lot of research being done to create ceramics piezoelectric with certain qualities for multiple applications [8-10]. The ceramic (BT) BaTiO3 was found to have a large Ɛr of 1100, which is ten times greater than the maximum documented Ɛr value for rutile TiO2 at the time of its invention. A phonograph pickup that was created in 1947 was the first commercially available product made of BT. A historical turning point in piezoelectric research was thought to have been reached in the 1950s with the finding of Pb(Zr1-xTix)O3 or (1-x)PbTiO3-xPbZrO3 ceramics, which are commonly exploited and utilized piezoelectric materials [1]. The ensuing research on the binary system established the significance of position-induced phase transitions on piezoelectric behavior, highlighting the significance of the MPB (morphotropic phase boundary) concept [11]. In PbTiO3 (PT), ultrahigh piezoelectricity, single crystal piezoelectric and exceptional electromechanical coupling capabilities were found between the 1980s and 1990s [12]. When compared to traditional piezoelectric ceramics, these have a 3 to 10 times higher piezoelectric effect. Numerous studies have been conducted on relaxor-PT single crystals, which exhibit a large piezoelectric constant and high electro-mechanical coupling factors that are thought to be closely related to designed domain topologies [12, 13]. The study of relaxor-PT single crystal ferroelectrics has advanced significantly in recent years due to their exceptional features. Lead is a very poisonous substance that can harm a person's kidneys, brain, and nervous system, as is common knowledge. PZT use has increased, which has led to more harmful lead being released into the environment. As a result, international governments have passed legislation outlawing the utilization of lead-contained materials in the production of a variety of goods. PZT was classified as a hazardous material by the European Union in 2003, and safer substitutes had to be used in its place [14, 15]. After that, Asian nations like Japan, China, and the Republic of Korea passed policies to limit the utilization of lead-contained items [16, 17]. These guidelines boosted the quest for lead-free piezoceramics and led to the development of novel materials, including sodium bismuth titanate-based and potassium sodium niobate [18].
2.1. Perovskite-Type Piezoelectric Substances
Traditionally, material science has been one of the most fascinating subjects as far as applications are concerned [19-21]. The advent of nanotechnology made it possible to use the materials like spinel ferrites for applications in targeted drug delivery, wastewater treatment, biomedical applications, sensors, actuators and many other electronic devices [22-24]. However, piezoelectric materials initiated a different league. The piezoelectric effect occurs in twenty of 32 crystal classes, and these crystals are always non-centrosymmetric (lacking a center of symmetry). Berlinite and quartz are examples of naturally occurring minerals that have this effect because of their crystalline structure. A process called poling is used to impart the piezoelectric property to engineered materials like BT and PZT. The most often studied systems are ferroelectrics with tungsten bronze structure, perovskite, ilmenite, and bismuth layers. The perovskite structure crystallizes the most significant piezoelectric ceramics with the best characteristics. By comparing other materials, perovskite-structured piezoelectric materials often displayed a greater piezoelectric effect. As a result, the research community has shown a lot of interest in perovskite structured materials. Highly symmetrically distributed constitutional atoms in the perovskite structure enable the unit cell to easily deform, leading to several ferroelectrically active non-cubic phases, including orthorhombic (O), rhombohedral (R), monoclinic (M), and tetragonal (T). Fig. (2) shows the factual ABO3 structure, and a perovskite structure standard formula is ABO3, where “A” and “B” are two cations that differ greatly in size, with “A” atoms typically being larger than “B” atoms [25-27]. Alkaline earth elements or rare earth (RE) elements are frequently found as A-site ions in the lattice corners of this configuration. The transition metal elements in the 3d, 4d, and 5d dimensions can be the B-site ions at the lattice's center. Corner-linked oxygen octahedral makes up the ABO3 structure, with the smaller cation filling the octahedral holes and the bigger cation doing the same for the dodecahedral holes.
A perovskite material must undergo non-centrosymmetric alterations to the ABO3 perovskite structure to show piezoelectric activity [28]. Depending on the modification, the axes of the cell may shift in many directions; the angles may deete from the correct angle (R phase) or both (M phase). Initially, for the predic- tion of the perovskite structure’s stability, the Goldschmidt tolerance factor t is typically used. It is defined as follows [29]:
(1)where Ro, RA, and RB are the ionic radii of the oxygen ion, large cation (A site), and small cation (B site), respectively. The structure of perovskite is stable only if the factor of tolerance falls between 0.90 and 1.1. A chemical with the formula ABO3 often does not crystallize in the perovskite structure at larger t deviations from unity. A-site and O-site vacancies are tolerated by perovskite structures; however, there are very few examples of perovskite structures with B-site vacancies. Additionally, perovskite structures that have tolerance factors t in the region of 0.95 and 1.0 are often cubic, whereas those with lower t values are slightly deformed but not ferroelectric, and those slightly over 1.0 are likely to be [30]. Because the unit cell is capable of so many various distortions, the perovskite structure is incredibly versatile. It is distortable into a wide range of phases [31]: Tetragonal (T) cells are produced in 1D along the cubic [100] direction, orthorhombic (O) cells are produced in 2D along the [110] direction, rhombohedral (R) cells are produced in three dimensions along the [111] direction, and monoclinic (M) and triclinic (Tr) cells are produced in 3D along arbitrary [hkl] or [hk0] directions. Given that the cube has three equivalent [100] directions, [100], [010], and [001], a spontaneous polarization can form in any of these six directions. Accordingly, the T structure has 6 potential domain variants, the R structure has 8, the O structure has 12, the M structure has 24, and the Tr structure has 48 potential domain variants. However, the synthesis procedure plays an important role in deciding the properties of a material, especially nanomaterials [32-34]. Like the spinel ferrites where the most important and prominent phase is cubic, for piezoelectric materials, the most stable phase is cubic [35-37]. Whereas the distortion in the cubic phase leads to the development of the other three structures.
Fig. (2)) Schematic diagram of perovskite structure.2.2. Utilizations of Piezoelectric Materials
Transformers, actuators, capacitors, resonators, transducers, sensors, and other devices have all made substantial use of piezoelectric materials [38-40]. The underwater development of an ultrasonic detector using a tiny mosaic quartz transducer glued amid two steel plates was one of the first uses for piezoelectric materials throughout the 1st World War [3]. Signal filters, ultrasonic transducers, and microphones are a few examples of piezoelectric devices utilized in non-resonating or resonating modes that have seen further development in applications. However, several devices were found to not be profitably viable due to the restricted performance of the materials at that time. As science and technology developed, more and more high-performance piezoelectric materials were discovered, which facilitated the ongoing advancement of piezoelectric devices. Due to this strategy, a substantial commercial market has been developed for piezoelectric products, encompassing both general-use products and highly specialized machinery [41].
3. ELECTRIC FIELD-INDUCED STRAIN IN PEROVSKITE-BASED MATERIALS
As explained previously, the very symmetrically dispersed constitutional atoms make it possible for the unit cell to deform readily, leading to the existence of a variety of ferroelectrically-active non-cubic phases in the perovskite structure, for example, the R(rhombohedral, O (orthorhombic), T (tetragonal), or M (monoclinic) phases. For chemical modification, interstitial sites and high spatial tolerance for substitute atoms are advantageous since they let one tailor the material's functional properties. The physical deformation of these perovskite-structured ceramics is induced by an external electric field in response to modifications in their macroscopic polarization state [42]. Additionally, the applied field’s strength is correlated with the ceramic perovskite-structured displacement. The strain-induced electric field, which comprises extrinsic and intrinsic components, is a feature in perovskite materials. Electrostriction and piezoelectric phenomena are the sources of intrinsic contributions, whereas domain wall movement in materials with ferroelectric/ferroelastic domain structures is the source of extrinsic contributions.
3.1. Piezoelectric Effect
When a material has a non-centrosymmetric crystal structure, the piezoelectric effect develops. This effect is a charge displacement that happens when mechanical stress is applied (the direct piezoelectric effect) or when a mechanical strain occurs when an electric field is applied (the reverse piezoelectric effect). In contrast, the piezoelectric effect depends linearly on the applied electric field and strain. A piezoelectric material can be stretched or compressed based on the opposite piezoelectric effect, depending on the material’s polarity and the direction of the applied field [39, 43]. Piezoelectric strain can be expressed in tensor notation by using the formula
(2)where Ei is the applied field, Sjk is the piezoelectric strain, and dijk is a piezoelectric coefficient’s third-ranked tensor. This formula follows Einstein's standard. A poled lithium niobate LiNbO3 single crystal's strain-electric field (S-E) loop is shown in Fig. (3) at a frequency of 10 Hz, demonstrating a linear and non-hysteretic strain-electric field loop. It is possible to consider that the LiNbO3 single crystal's linear strain response is mostly inherently piezoelectric.
Fig. (3)) Strain vs Electric field (S-E) graph of Poled LiNbO3 at 10 Hz. (Reproduced by permission from the reference number [31], License number 5562870599818, copyright 2019, Elsevier).By finding the piezoelectric constant d33 sign, it is clear from the image that the polarization's macroscopic orientation, in this case, was parallel to the electric field. Given that the strain created in the region between points a and b was positive (Fig. 3), the sample will, in this case, elongate in the direction of the electric field. It is obvious that after the electric field was unloaded, the strain decreased in the area between b and c. The electric field produced a reversal sign when it was inverted in the c, d range. Additionally, domain switching was not induced during the application of the electric field since the coercive field (Ec) of single crystal LiNbO3 was significantly greater than the 60 kV/cm of the maximum applied field. The piezoelectric effect was probably the main cause of the strain since a polarized LiNbO3 single crystal displayed a linear and non-hysteretic S-E response.
3.2. Electrostriction
Electrostriction, which can occur in centrosymmetric or non-centrosymmetric crystal structures when a material is placed in the applied field, and caused by a small displacement of ions inside the crystal lattice [44]. The best observation of the electrostriction effect is in paraelectric materials because it is extremely weak in piezoelectric materials. A paraelectric substance that is at a higher temperature gets polarized when an external electric field is applied. The product of the dielectric susceptibility (χ) and the induced polarization (P), which is proportional to the applied electric field (E), can be written as follows:
(3)where Ɛo represents the vacuum's dielectric constant and χ stands for a linear dielectric constant. P is inversely proportional to E in this situation. As a result, the strain caused by the electromechanical coupling can be defined as either a polarization, Pk or a power series of the applied field, Ek. The second-ranked tensors strain (Sij) and fourth-ranked Mijkl and Qijkl are electrostriction tensors. El and Ek are the electric field vector components, and Pk and Pl are the polarization vector components, and
(4)(5)The component in Equation (4) denotes the reverse piezoelectric effect’s contribution, while the term in Equation (5) indicates electrostriction.
(6)where P represents the polarization, and Qij denotes the electrostrictive coefficient, which gives the strain contribution by electrostriction. The BNT-based ceramics exhibit electrostrictive behavior in Fig. (4a). As it is evident, the S-E and P-E loops were mildly hysteretic, signifying that the electrostriction effect was primarily responsible for the strain [45]. With -S11/S33, the deformation of Poisson's ratio-type by a material remains constant during electrical cycling, resulting in a quadratic rise in volume [1, 7].
Fig. (4)) Electrostrictive behavior of (a) 0.54BNT-0.36BT-0.10KNN, (b) a commercial ferroelectric PZT (PIC151, PI Ceramics), and (c) antiferroelectric Pb0.99Nb0.02[(Zr0.57Sn0.43)0.7Ti0.3]0.98O3 (PNSZT), with polarization vs. electric field loop. (Reproduced by permission from the reference number [31], License number 5562870599818, copyright 2019, Elsevier).3.3. Domain Switching
The strain brought on by an electric field is increased in ferroelectric domain-structured electroceramics. Instead of the 180° domain reorientation that occurs when the field is applied, this strain is created by the movement of the ferroelectric domain walls of non-180° [46, 47]. This movement of domain wall field-triggered often leads to hysteretic and nonlinear S-E loops, leading to a far more complicated behavior when evaluated for intrinsic electrostriction and piezoelectricity [48]. In prior work, the movement of the domain wall affecting the electric field strain loops of various ferroelectrics has been thoroughly investigated [49-51]. One of the usual ferroelectrics examined was the PZT (soft). Fig. (4b) represents the strain in hysteresis and polarization in soft PZT ferroelectric materials. When an applied field is present, the domain walls of the PZT move, which serves to induce simultaneous changes in strain and polarization. Therefore, together with the electrostriction and piezoelectric effect, the movement of domain wall contribution is incorporated into the material's strain response. A hysteresis strain and nonlinear complex behavior with S-E loop characteristics look like a butterfly result from this event. When a weak field (electric) is introduced, the material displays electrostrictive properties [52]. The movement of the domain wall’s major contribution to the total strain is reached when the applied field reaches a definite level, which is frequently greater than the poling field. This is frequently marginally different from the coercive field (Ec) and can be explained by the hysteresis loop polarization’s inflection point [53, 54]. Along with polarity flipping in the direction that is closest to the direction of the field and where the spontaneous polarization value approaches asymptotically, massive randomly oriented ferroelectric domain alignment along the field direction also takes place. When the applied electric field is removed, the material enters a remnant state at zero electric fields because some of the ferroelectric reoriented domains steadily switch back based on their vigorous stability, while a sizable portion of ferroelectric reoriented domains stay in their evaluated directions [55]. For some ferroelectric old perovskites, a considerable electric-strain effect was produced via a domain-switching reversible approach. With the use of a universal “symmetry-conforming principle” of point defects (also known as the “defect symmetry principle”), this system produces a storage force for domain switching and then accomplishes flexible domain switching [56]. The fundamental idea of this theory is that when a crystal is in equilibrium, point defects in crystals follow the symmetry of the crystal due to an as-yet-unidentified “statistical symmetry” [57, 58]. This technique was first proposed for ferroelastic materials and was utilized to characterize the domain-switching reversible phenomena in old ferroelastic alloys. Recently, ferroelectrics have successfully used it.
Fig. (5) depicts the recoverable domain-switching procedure for ferroelectrics. Throughout the “aging” process, the movable defects move in a way that is reliable with the symmetry of the crystal. PD-Defect polarization and spontaneous polarization (PS) are simultaneously produced and aligned along the same direction (Fig. 5a, b). When a field E is applied to old ferroelectrics, a diffusion-less mechanism causes PS to reorient while PD stays the same (Fig. 5b, c). After E is taken out, the strength of PD changes PS to its actual state (Fig. 5c, b). On a macroscopic level, it is possible to assume that a reversible domain switching mechanism will be associated with a significant nonlinear recoverable electrostrain (Fig. 5d).
Fig. (5)) Recoverable domain switching mechanism for ferroelectrics.3.4. Volume Adjustment
There are other perovskite-type materials that are identified as vigorously stable when ion’s rows are spontaneously polarized and alternately oriented in order that the net macroscopic polarization is zero, including lead zirconate (PbZrO3 (PZ)), AgNbO3, and NaNbO3 (NN), among others [59, 60]. These materials lack piezoelectricity because of the center of symmetry that distinguishes them from ferroelectrics (FE) and gives them the name anti-ferroelectrics (AFE). When the free energies of the two states are comparative, an external applied field can produce an FE state in an AFE, causing a twofold hysteresis in the loop of polarization hysteresis (Fig. 6) [61]. The inflection points experienced throughout the descending and ascending electric fields are the FE-to-AFE switching field (EFA) and AFE-to-FE switching field (EAF), respectively. For convenient applications such as digital displacement transducers, energy storage capacitors, solid-state cooling devices, and others, it is crucial to engineer the size of EAF and EFA [62]. The bidirectional transition among the AFE and FE states includes the emergence and removal of a central symmetry because VFE > VPE > VAFE [63]. This volume shift is assumed to be the main contributor to the electric field-induced strain in AFE materials [64].
Fig. (6)) Diesel injector of the common rail type with a piezoelectric multilayer actuator (Courtesy by Denso Corp).4. TRENDS IN APPLICATION DEVELOPMENT
Instead of focusing on more traditional advances in the commercial market, the author, in this part, emphasizes new trends in crisis technology and sustainability.
4.1. Standard Technologies
The international system for environmental sustainability, in particular, drove new advancements in the application area for renewable energy harvesting systems, air pollution caused by diesel injection valves, wastewater treatment, and ultrasonic hazardous waste disposal technologies [65].
4.1.1. Ultrasonic Disposal Technology
In the house, ultrasonic lens cleaner is frequently used. Silicon wafer and liquid crystal glass substrate production processes make extensive use of industrial ultrasonic cleaners. Along with a Sharp Corporation washing machine, Honda Electronics installed another ultrasonic cleaner [66]. Their device can clean the collar of a shirt by creating water cavitation using an L-L coupler horn. It is interesting that by utilizing this method, we may greatly lower the amount of detergent—one of the main contributors to river contamination [67]. By increasing the water cavitation's power level, we can turn hazardous waste into harmless waste because cavitation produces more than 3000 °C in a small area for a brief time. Dioxin, trichloroethylene, PCBs, and environmental hormones are among the hazardous pollutants that can be found in groundwater or sewer water [68]. It is common knowledge that when burned at a low temperature, dioxin transforms into another dangerous substance, yet burning it at a high enough temperature causes it to become harmless. Although the normal water temperature only rises to 50°C, ultrasonic cavitation is particularly valuable for this purpose.
4.1.2. Contaminated Gas Reduction
When assessing the total energy used in the procedures from tank to wheel and well to tank for producing petrol, diesel engines were advised over conventional gasoline vehicles from the perspective of energy conservation and global warming [69]. The energy efficiency of high-octane gasoline is superior to diesel oil when expressed as the total energy needed to actualize one unit of driving distance for a vehicle (MJ/km). Gasoline, however, is inferior to diesel because of the substantial amount of electric energy needed for purification [70]. However, the traditional diesel engine produces hazardous exhaust pollutants like SOx and NOx, as is well known. Siemens, Bosch, and Toyota created new diesel injection valves with PZT-based multilayered piezoelectric actuators to address this issue. This form of common rail diesel injection valve with a multilayer piezo-actuator, which generates high-pressure fuel and rapid injection control, is shown in Fig. (6). The maximum reliability of these devices over a long length of time (10 years) at a high temperature (150 °C) has been attained [71]. To improve burning efficiency and reduce harmful exhaust emissions, the PZT piezoelectric actuator is essential.
4.1.3. New Energy-Harvesting Technologies
Piezoelectric energy harvesting is one of the most recent study areas of interest. Instead of being consumed as Joule heat in the original dampers, the cyclic electric field created in the piezoelectric plate by the environmental noise vibration is now stored in a rechargeable battery. A piezoelectric windmill designed by NEC-Tokin uses the wind generated by moving cars to power an LED traffic light array system. The Lightning switchTM (remote switch for room lighting, employing a unimorph piezoelectric component) by PulseSwitch Systems, VA is a popular product (million sellers) on the commercial market [72, 73]. In addition to improving living conditions, Lightning SwitchTM can significantly lower the cost of building a home since it uses significantly less copper electric wire and aligned work. The Penn State team developed piezoelectric devices that gather energy based on a 29 mmϕ, 1-2 mm thick “Cymbal” structure that can produce up to 100 mW of electric energy when subjected to engine vibration [68, 69]. This application pursued vibration dampening and energy gathering at the same time or two “rabbits”. A washer-like energy collecting sheet was created for a hybrid car application, aiming for 1 W-level continual accumulation to a fuel cell by fusing three cymbals in a rubber composite.
4.1.4. Medical Devices
Medical technology advancements in developed nations have been spurred by the economic downturn and the aging population (the average age of women in Japan is 87 years old). Small size, rapid reaction, and high energy density are the advantages of piezoelectric actuators over traditional electromagnetic motors, as we explained in a study [74]. Micro-motors have been tested in artificial insemination systems and medical catheter applications (blood clot clearance). Modern magnetic resonance imaging (MRI) systems use large ultrasonic motors to disperse magnetic interference. Devices made with piezo-MEMS are intended to be used as medicine delivery systems, blood tests, etc.
4.2. Emerging Technologies
Natural disasters (hurricanes, earthquakes, tornadoes, tsunamis, lightning, etc.),Epidemic/infectious diseases (smallpox, polio, measles, and HIV),Catastrophic accidents (such as the Three-Mile-Island core meltdown accident and the BP oil spill),Intentional damage (such as terrorism and criminal activity), andCivil wars, wars, and territorial aggression are the five categories into which crisis technologies are divided [72].4.2.1. Infectious Illnesses
These five are related to one another because infectious or contagious diseases have a connection to terrorism. In 2001, anthrax attacks on politicians occurred in the US. At Penn State University, Pezeshk, Gao, and Uchino created a portable hypochlorous acid disinfection system employing a piezoelectric ultrasonic humidifier to counteract the biological onslaught [73]. To protect office and hospital buildings from diseases like SARS and anthrax, hypochlorous acid, a potent disinfectant with no adverse effects for people, should be used to clean them. High levels of disinfection can be anticipated when the acidic solution is atomized. Since it naturally breaks down after a few hours, this acid is not offered as a pure solution for sale [62]. To create hypochlorous acid from brine, we created an electrolytic cell that is resistant to corrosion. To create tiny droplets of the diluted acid, an ultrasonic piezoelectric atomizer was used.
4.2.2. Natural Calamities
The following are the research themes that are urgently needed in the sensor /actuator area concerning natural disasters: (1) earthquake and tornado prediction technologies; (2) surveillance techniques and precise monitoring; (3) technologies for managing and gathering crisis information; (4) rescue technologies (aerial, self-directed unmanned underwater, robots, and vehicles). Recently, PMN-PT single crystals have been extensively studied for use in high-resolution surveillance sonar systems [75-77].
CONCLUSION
The Curie siblings discovered the piezoelectric effect in 1880, and since then, it has been substantially studied and applied to a wide range of technologies. One-dimensional piezoelectric nanostructures have recently drawn a lot of attention due to their potential for usage in cutting-edge technologies. Due to their multifunctional characteristics, including ferroelectricity, high-temperature superconductivity, and enormous magnetoresistance, 1D perovskite (ABO3) nanocrystals have received a lot of attention in the past two decades. The global trend toward ecological sustainability propelled new advancements in application areas such as diesel injection valves for air pollution control, piezoelectric renewable energy harvesting systems, and ultrasonic hazardous waste disposal. Applications for piezoelectric perovskites in disaster avoidance include tsunami /earthquake monitoring and safety systems for nuclear power plants. In the twenty-first century, the author aspires to “the glory of piezoelectric perovskites”.
