Search Results (732)

The article presents research on a wide frequency range piezo sensor applied to surfaces by touch. It details the design of the piezo sensor, its operating principles, and usage characteristics. Calculations of the main vibration forms and modes, modeling, and experimental verifications are provided. The objective of the research was to create a lightweight, ergonomic device that enables quick detection and testing of ultrasonic vibrations on objects (ultrasonic concentrators, their replaceable tips, concentrator mounting structures, device casings, etc.) with a brief touch—up to 1 s. After optimizing the design parameters and conducting tests, it was determined that the piezo sensor identifies vibrations in the range of 20–96 kHz, which is a commonly used range in ultrasonic vibration systems (UVS). A distinctive feature of the sensor is that in this frequency range, it does not generate amplitude peaks, and its structural elements do not enter into the resonances of lower modes (1–5). The piezo sensor is not intended to determine precise vibration amplitudes and forms. It is designed to quickly find the points of minimum and maximum vibrations in vibrating objects, where precise measurements will later be conducted. The conducted research will assist in the design and manufacturing of such devices. Full article

While synthetic biology has traditionally focused on creating biological systems often through genetic engineering, emerging technologies, for example, implantable pacemakers with integrated piezo-electric and tribo-electric materials are beginning to enlarge the classical domain into what we call symbiotic synthetic biology. These devices are permanently attached to a body, although non-living or genetically unaltered, and closely mimic biological behavior by harvesting biomechanical energy and providing functions, such as autonomous heart pacing. They form active interfaces with human tissues and operate as hybrid systems, similar to synthetic organs. In this context, the present paper first presents a short summary of previous in vivo studies on piezo-electric composites in relation to their deployment as battery-less pacemakers. This is then followed by a summary of a recent theoretical work using a damped harmonic resonance model, which is being extended to mimic the functioning of such devices. We then extend the theoretical study further to include new solutions and obtain a sum rule for the power output per cycle in such systems. In closing, we present our quantitative understanding to explore the modulation of the quantum vacuum energy (Casimir effect) by periodic body movements to power pacemakers. Taken together, the present work provides the scientific foundation of the next generation bio-integrated intelligent implementation. Full article

Background: Developmental and Epileptic Encephalopathy (DEE) is a severe and heterogeneous neurological disorder in infancy/early childhood. DEE’s genetic and phenotypic variability complicates diagnosis and treatment. This retrospective study aimed to identify genetic variants and explore genotype–phenotype correlations in children with DEE using a targeted epilepsy gene panel (TGP) and Whole Exome Sequencing (WES). Patients and Methods: Medical records of children who underwent custom-designed 55-gene TGP and WES were reviewed. The diagnostic yield of each method was determined based on the detection of pathogenic (P) and likely pathogenic (LP) variants. Results: A total of 129 patients (66 males, 63 females) underwent TGP, which identified P/LP variants in 29 cases (22.48%). Variants were detected in SCN1A, KCNQ2, STXBP1, CDKL5, PCDH19, PLCB1, WWOX, SCN2A, FGF12, HCN1, SCN8A, and SLC35A2. WES further identified several variants in children with West syndrome. A TSC1 variant was detected in a patient without cutaneous stigmata of tuberous sclerosis complex. The NALCN variant in a patient was linked to Infantile Hypotonia with Psychomotor Retardation and Characteristic Facies 1. A CTBP1 variant associated with extremely rare Hypotonia, Ataxia, Developmental Delay, and Tooth Enamel Defect Syndrome was detected in another patient. A PIEZO2 variant—associated with Marden–Walker syndrome—was found in a child with Early Infantile Developmental and Epileptic Encephalopathy. Conclusions: These findings highlight the extensive genetic heterogeneity and phenotypic variability of DEE. WES demonstrates substantial value in identifying novel gene-disease associations and may be considered as a first-tier diagnostic tool in epilepsy and DEE. Full article

Recent research has focused on energy recovery and storage technologies. One of the materials allowing the recovery of dissipated energy is the piezoelectric material (PE). These functional materials perform reversible energy conversion, transforming electrical energy into mechanical and vice versa. In this study, we investigate the recovery of vibratory energy in vehicle suspension systems—energy traditionally dissipated by conventional shock absorbers—using piezoelectric materials to capture this wasted energy and redirect it to the vehicle’s auxiliary power supply network. We propose an integrated electromechanical model incorporating piezoelectric actuators in parallel with the suspension mechanism. The collected energy is processed and stored for later use in powering accessories such as windows and mirrors. The idea is to integrate renewable energy sources to optimize the performance of the vehicle. We proposed a Multiphysics model of the system under a software used to this type of modeling (Simcenter AMESim v1610_student). The simulation results of the system and its various sub-systems are presented for studying the piezo-actuator response to reduce consumption and increase energy performance in a vehicle. These findings will undergo experimental validation in the project’s subsequent phase. Full article

Mechanical stress on the glomerular filtration barrier (GFB) exposes podocytes to hydrostatic pressure. Their mechanosensitivity is established, yet the underlying mechanotransduction pathways and responses under hypertension remain unclear. This review examines the mechanical stresses experienced by podocytes in both physiologic and hypertensive conditions and updates the latest extracorporeal techniques used to simulate these forces. Additionally, this review discusses how podocytes respond to these mechanical forces and elucidates the detailed molecular mechanisms involved. Furthermore, we summarize potential protective mechanisms that enable podocytes to withstand mechanical challenges and propose novel therapeutic strategies to delay the progression of hypertensive nephropathy. This review uniquely underscores the importance of biomechanical factors in disease progression and integrates emerging therapeutic strategies targeting podocyte mechanotransduction, offering a novel biomechanical framework for delaying hypertensive nephropathy progression. Full article

Although hypergravity may influence cardiac mechanosensitivity, the effects on specific ion channels remain inadequately understood. This research examined the effects of long-term hypergravity on the functional activity and transcriptional expression of mechanosensitive channels (MSCs) in rat ventricular cardiomyocytes. After 14 days of exposure to 4g, rats were subjected to molecular and electrophysiological analyses. Significant remodeling of MSC-encoding genes was revealed by RNA-seq. Trpm7 (+41.23%, p = 0.0073) and Trpc1 (+68.23%, p = 0.0026) were significantly upregulated among non-selective cation channels, while Trpv2 (−62.19%, p = 0.0044) and Piezo2 (−57.58%, p = 0.0079) were significantly downregulated. Kcnmb1 (−47.84%, p = 0.0203) was suppressed, whereas Traak/K2P4.1 showed a strong increase (+239.48%, p = 0.0092), among K⁺-selective MSCs. Furthermore, Kir6.1 was significantly downregulated (−75.8%, p = 0.0085), whereas Kir6.2 was significantly upregulated (+38.58%, p = 0.0317). These results suggest targeted transcriptional reprogramming that suppresses pathways associated with maladaptive Ca²⁺ influx while enhancing Ca²⁺-permeable mechanosensitive channels alongside stabilized K⁺ conductance. At the structural level, cardiomyocytes from hypergravity exposure showed a 44% increase in membrane capacitance, consistent with hypertrophic remodeling, and sarcomere elongation (p < 0.001). Functionally, stretch-activated current (I_SAC) was markedly hypersensitive in patch-clamp analysis: currents were induced at very small displacements (1–2 µm) and were significantly larger under 4–10 µm stretch (222–107% of control values). These findings indicate that chronic hypergravity induces coordinated molecular, structural, and functional remodeling of cardiomyocytes, characterized by increased membrane excitability, compensatory stabilizing mechanisms, and enhanced Ca²⁺ signaling. This demonstrates the flexibility of cardiac mechanotransduction under prolonged gravitational stress, with potential implications for understanding cardiovascular risks, arrhythmias, and hypertrophy associated with altered gravity environments. Full article

Ferroelectric materials have attracted great attention for photocatalytic hydrogen (H₂) evolution due to their internal depolarization fields that promote carrier separation and directional migration. However, conventional inorganic ferroelectrics often suffer from wide band gaps and low conductivity, limiting their solar-to-hydrogen conversion efficiency. Here, we report a two-dimensional (2D) multilayered perovskite ferroelectric, [butylammonium]₂[ethylammonium]₂Pb₃I₁₀ (BAPI), which integrates robust spontaneous polarization (P_s) and excellent semiconductor properties to enable efficient photocatalysis. Under simultaneous light and ultrasonic excitation, BAPI/Pt (1 wt%) achieves a H₂ evolution rate of 1256 μmol g⁻¹ h⁻¹, which is twice that under light alone, due to dynamic polarization modulation that mitigates ionic screening and enhances internal electric fields. Notably, this enhancement vanishes when BAPI transitions to a centrosymmetric, nonpolar phase at 323 K, confirming the critical role of P_s. These findings offer a new pathway toward high-performance ferroelectric photocatalysts for solar hydrogen production. Full article

Intracortical microelectrode arrays (MEAs) are tools for recording and stimulating neural activity, with potential applications in prosthetic control and treatment of neurological disorders. However, when chronically implanted, the long-term functionality of MEAs is hindered by the foreign body response (FBR), characterized by gliosis, neuronal loss, and the formation of a glial scar encapsulating layer. This response begins immediately after implantation and is exacerbated by factors such as brain micromotion and the mechanical mismatch between stiff electrodes and soft brain tissue, leading to signal degradation. Despite progress in mitigating these issues, the underlying mechanisms of the brain’s response to MEA implantation remain unclear, particularly regarding how cells sense and respond to the associated mechanical forces. Mechanosensitive ion channels, such as the Piezo family, are key mediators of cellular responses to mechanical stimuli. In this study, silicon-based NeuroNexus MEAs consisting of four shanks were implanted in the rat somatosensory cortex for sixteen weeks. Weekly neural recordings were conducted to assess signal quality over time, revealing a decline in active electrode yield and signal amplitude. Immunohistochemical analysis showed an increase in GFAP intensity and decreased neuronal density near the implant site. Furthermore, Piezo1—but not Piezo2—was strongly expressed in GFAP-positive astrocytes within 25 µm of the implant. Piezo2 expression appeared relatively uniform within each brain slice, both in and around the MEA implantation site across cortical layers. Our study builds on previous work by demonstrating a potential role of Piezo1 in the chronic FBR induced by MEA implantation over a 16-week period. Our findings highlight Piezo1 as the primary mechanosensitive channel driving chronic FBR, suggesting it may be a target for improving MEA design and long-term functionality. Full article

Dual-loop control enhances the bandwidth of piezo-actuated nanopositioning systems via inner-loop state feedback controller suppressing lightly damped resonance and outer-loop tracking controller eliminating hysteresis nonlinearity. However, the traditional framework based on the continuous-time low-order model suffers from control performance degradation. To address this issue, this paper proposes a dual-loop control framework based on the discrete-time high-order model. In this framework, the discrete-time linear quadratic regulator extends theoretical bandwidth through simultaneous parameter optimization, and direct discrete implementation of the high-order state feedback controller and an integrator improves control precision by reducing model mismatch and controller discretization errors. Experiments are conducted on a custom-designed piezo-actuated system. Experimental frequency response of the system with the developed framework agrees well with the theoretical one, and the actual bandwidth is improved to 8248 Hz, which is better than 3920 Hz (continuous-time high-order model) and 6610 Hz (discrete-time low-order model), and exceeds open-loop resonant frequency 6352 Hz. Step response and trajectory tracking tests also demonstrate the effectiveness of the developed framework. Full article

MEMS switches offer great advantages over solid-state and conventional electromechanical switches, including a compact size and high isolation. This paper presents a novel silicon-to-silicon (Si-to-Si) MEMS switch featuring two suspended actuated platforms for DC power switching applications. The proposed design uniquely incorporates dual suspended chevron actuators, enabling bidirectional actuation, enhancing force generation, and improving overall switching performance. Leveraging the robustness of silicon, this Si-to-Si contact switch aims to enhance the reliability of MEMS-based DC power switches. Testing of a fabricated device in the PiezoMUMPs process demonstrated that a 2 μm initial contact gap closes at 1.1 V_DC, with a total actuation power of 246 mW. The switch exhibits a linear voltage–current response up to 5 mA of switching current and achieves a minimum contact resistance of ~294 ± 2 Ω, one of the lowest reported for Si-to-Si contacts. This low contact resistance is attributed to the suspended contact platforms, which mitigate misalignment. The measured response time was 4 ms for turn-on and 2.5 ms for turn-off. This switch withstood a breakdown voltage of up to 376 V across the 2 µm contact gap. Moreover, the 200 nm thick oxide layer separating the actuation and signal lines exhibited breakdown at 183 V. These findings highlight the potential of the switch for high-voltage applications and pave the way for further enhancements to improve its reliability in harsh environments. Full article

Diastolic heart failure, also referred to as heart failure with preserved ejection fraction (HFpEF), is a complex cardiovascular clinical syndrome that is a growing health burden worldwide. Patients present with high abnormal left ventricular filling pressures but normal ejection fraction that can progress to diastolic heart failure and death. The causes of diastolic dysfunction are varied, and pharmacotherapies are limited to managing the symptoms of the disease. At the level of the myocyte, cytoskeletal disarray and mitochondrial dysfunction are common features associated with diastolic disease. Understanding the mechanisms of abnormal diastolic filling pressures is necessary to identify novel treatments, which remains an area of significant unmet need. In this article, we discuss the mechanisms of maladaptive feedback contributing to increased extracellular stiffness, cytoskeletal disarray, and mitochondrial dysfunction in diastolic heart failure. Since the mechanisms are complex, understanding the contributing factors provides opportunities for the development of novel drug targets. These will be discussed and examined in the context of current therapy. Full article

Spinal health depends on the dynamic interplay between mechanical forces, biochemical signaling, and cellular behavior. This review explores how key molecular pathways, including integrin, yeas-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ), Piezo, and Wingless/Integrated (Wnt) with β-catenin, actively shape the structural and functional integrity of spinal tissues. These signaling mechanisms respond to physical cues and interact with inflammatory mediators such as interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α), driving changes that lead to disc degeneration, vertebral fractures, spinal cord injury, and ligament failure. New research is emerging that shows scaffold designs that can directly harness these pathways. Further, new stem cell-based therapies have been shown to promote disc regeneration through targeted differentiation and paracrine signaling. Interestingly, many novel bone and ligament scaffolds are modulating anti-inflammatory signals to enhance tissue repair and integration, as well as prevent scaffold degradation. Neural scaffolds are also arising. These mimic spinal biomechanics and activate Piezo signaling to guide axonal growth and restore motor function. Scientists have begun combining these biological platforms with brain–computer interface technology to restore movement and sensory feedback in patients with severe spinal damage. Although this technology is not fully clinically ready, this field is advancing rapidly. As implantable technology can now mimic physiological processes, molecular signaling, biomechanical design, and neurotechnology opens new possibilities for restoring spinal function and improving the quality of life for individuals with spinal disorders. Full article

Mechanical forces shape immune responses in both health and disease. PIEZO1 and PIEZO2, two mechanosensitive ion channels, have emerged as critical transducers of these forces, influencing inflammation, pain, fibrosis, and neuroimmune regulation. This review aims to synthesize the current evidence on the role of PIEZO channels in mechano-inflammation, with a specific focus on their regulatory function in neuroimmune crosstalk. A comprehensive narrative synthesis was performed using the literature from PubMed, Scopus, and Web of Science up to June 2025. Experimental, translational, and mechanistic studies involving PIEZO channels in inflammatory, fibrotic, and neuroimmune processes were included. PIEZO1 is broadly expressed in immune cells, fibroblasts, and endothelial cells, where it regulates calcium-dependent activation of pro-inflammatory pathways, such as NF-kB and STAT1. PIEZO2, enriched in sensory neurons, contributes to mechanosensory amplification of inflammatory pain. Both channels are mechanistically involved in neuroinflammation, glial activation, blood–brain barrier dysfunction, connective tissue fibrosis, and visceral hypersensitivity. PIEZO channels act as integrators of biomechanical and immunological signaling. Their roles as context-dependent gatekeepers of neuroimmune crosstalk make them attractive targets for novel therapies. Full article

Background: Rehabilitation of atrophic posterior mandibles using dental implants is often complicated by anatomical limitations, particularly the proximity of the inferior alveolar nerve (IAN). Techniques such as IAN lateralization and transposition enable implant placement but are associated with neurosensory disturbances (NSDs). This systematic review and meta-analysis aimed to assess the incidence, duration, and predictors of NSDs following IAN repositioning for implant placement and to evaluate the effectiveness of adjunctive methods like piezo-surgery and platelet-rich fibrin (PRF) in minimizing complications. Methods: Following PRISMA 2020 guidelines, a comprehensive search of electronic databases and gray literature identified 20 studies, including randomized controlled trials, prospective cohorts, and retrospective analyses published between 2009 and 2024. Outcomes analyzed included incidence of NSDs, recovery rates, implant stability quotient (ISQ), marginal bone loss, and implant success rates. Meta-analysis was performed using RevMan 5.3 software, with heterogeneity and publication bias assessed using standard Cochrane tools. Results: Transient NSDs occurred in 15–40% of cases, with higher rates observed in transposition techniques. Most patients experienced recovery within 6 months. Piezoelectric surgery significantly reduced the incidence and duration of NSDs compared to rotary instruments. Meta-analysis revealed no statistically significant differences between lateralization and transposition techniques in ISQ, marginal bone loss, success rate, or NSDs at 3 months (p > 0.05). PRF was associated with accelerated nerve recovery. IAN repositioning is effective for implant placement in atrophic mandibles with a risk of transient NSDs. Conclusions: Lateralization combined with piezo-surgery and PRF shows favorable outcomes in minimizing nerve injury and optimizing implant success. The PROSPERO registration code is as follows: CRD420251086835. Full article

Heart rate variability (HRV) is often modulated by pain; therefore, the objective of this study was to assess whether the induction of delayed-onset muscle soreness (DOMS) is already affected by HRV alterations during exercise, in spite of the fact that pain evolves only post-exercise. An isokinetic dynamometer was used to induce DOMS in this study on 19 young male elite handball players who were subjected to HRV measurements throughout a DOMS-inducing exercise session. The result of this study indicated that the heart rate (HR) dependence of time–frequency domain parameters could be described by an exponential-like function, while entropy showed a V-shaped function, with a minimum “turning point” separated by descending and ascending intervals. The DOMS protocol upshifted the time–frequency domain HRV parameters in the entire HR range, contrary to the sample entropy values that were systematically downshifted, indicative of an upregulated sympathetic tone. The group-averaged HR-dependent sample entropy function showed a nonlinear character under exercise, with lower values for higher DOMS than for the group with lower DOMS below the turning-point HR, and vice versa above it. The differences between the respective HRV(HR) point sets representing the low-DOMS and high-DOMS groups were quantified using a statistical method and found to be significant at the current sample size for all the HRV parameters used. Since oxidative stress is implicated in DOMS, we are the first to report that nonlinear alterations may impact HRV in a HR-dependent manner in DOMS using a Piezo2 interpretation. This finding provides further indirect evidence for an initiating neural microdamage that prevails under DOMS-inducing exercise, and the diagnostic detection of this point may provide control for avoiding further injury risk in sports and exercise activities. Full article