Vittayakorn, Wanwilai

Preferred name

Alternative Name

Vittayakorn, W.

Vittayakorn, Wanwilai C.

Main Affiliation

Integrated Innovative Technology

wanwilai.vi@kmitl.ac.th

Now showing 1 - 10 of 13

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Synergistic Enhancement of Mechanical and Dielectric Properties in BaTiO3/PDMS Composites for Flexible Energy Harvesting Devices
(2026-01-01)
Rerngroen, Nakulkarn
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Sasipongpan, Apinya
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Vittayakorn, Wanwilai
This study presents the fabrication, characterization, and performance evaluation of flexible piezoelectric composites based on polydimethylsiloxane embedded with varying volume fractions (0–25 vol%) of barium titanate nanoparticles. The composites were prepared via a conventional casting method and systematically analyzed to investigate the synergistic enhancement of their mechanical, dielectric, and piezoelectric properties. Structural and morphological analyses confirmed the retention of the crystalline BaTiO<inf>3</inf> phase and its uniform dispersion within the PDMS matrix, with some agglomeration observed at higher filler loadings. Mechanical testing revealed that the 20 vol% BaTiO<inf>3</inf> composite exhibited optimal tensile strength and flexibility. Dielectric measurements showed significant increase in the dielectric constant with increasing BaTiO<inf>3</inf> content, with the 25 vol% composite achieving a 100% enhancement compared to pure PDMS. Theoretical modeling was employed to compare experimental results with established effective medium theories. Under cyclic compression, the composites demonstrated a progressive increase in output voltage, reaching up to ~426 V at 25 vol% BaTiO<inf>3</inf>, surpassing performance reported in previous studies. Additionally, the incorporation of carbon nanotubes further enhanced dielectric efficiency and mechanical stretchability, although a slight reduction in piezoelectric output was observed. These results underscore the potential of BaTiO<inf>3</inf>/PDMS nanocomposites, with and without CNTs, for next-generation flexible energy harvesting devices.
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An architected silk fibroin-lignin multilayer with deep-level trapping states for high-output triboelectric nanogenerators
(2026-03-01)
Suktep, Natdanai
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Sae-tang, Chanachot
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Ukasi, Sirinya
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Pakawanit, Phakkhananan
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Supansomboon, Supitcha
Biopolymer-based triboelectric nanogenerators (B-TENGs) are promising power sources for sustainable and flexible electronics, but their performance is often limited by severe charge recombination at the triboelectric interface. To overcome this critical bottleneck, we report an architected multilayer B-TENG featuring a silk fibroin (SF)/MgAl LDH composite as the charge-generating layer and, to our knowledge, for the first time, a lignin-functionalized SF film as a dedicated charge-trapping layer. The strategic incorporation of lignin, an abundant and sustainable biopolymer, introduces deep-level electronic trapping states originating from its abundant aromatic moieties. That effectively suppresses interfacial charge recombination and prolongs charge lifetime. By optimizing the contents of MgAl LDH and lignin, the device achieves a measured open circuit output voltage ( V <inf> OC </inf>) and current density ( J <inf> SC </inf>) of 96 V and 6.56 μA/cm<sup>3</sup>, with a maximum output power ( P <inf> max </inf>) of 205 μW, corresponding to a power density of 22.7 μW/cm<sup>2</sup>. We also propose a mechanistic linking of deep-level traps to prolonged charge lifetime and increased net transferable charge. The interface-engineering strategy demonstrated here paves the way for developing high-performance and sustainable biopolymer-based TENGs and motion sensors.
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A highly sensitive disease pre-screening approach for glycosuria: Triboelectric sensing at the liquid-solid interface
(2025-03-15)
Pharino, Utchawadee
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Chaithaweep, Kanokwan
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Pongampai, Satana
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Chanlek, Narong
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Kothan, Suchart
Prescreening and disease detection offer significant benefits in the prevention of serious illnesses. Traditional screening methods for disease identification have been complex and expensive, often requiring invasive procedures, which can be both harmful and uncomfortable. To address these limitations, various non-invasive screening technologies have been developed. Among recent innovations, the liquid–solid interface concept has emerged as a promising avenue for nanogenerator applications, enabling the harvesting and sensing of liquid energy and substances. In this study, we introduce a liquid–solid interface triboelectric sensor (LS-TES) for non-invasive disease screening and sensing. The LS-TES, utilizing a double-electrode configuration, delivers an immediate electrical response upon droplet contact with the solid surface and top electrode. In the case of urine glucose monitoring, our findings demonstrate a significant reduction in electrical signals with increasing concentrations of glucose, as glucose molecules hinder electron transfer from water to the solid surface, thereby disrupting the formation of the electrical double layer at the liquid–solid interface. The sensor exhibits excellent glucose sensing performance within a concentration range of 0.2 mM to 14 mM, with a detection limit of 0.25 mM and a rapid response time of 5–10 s. The LS-TES is cost-effective, highly stable, and reusable, maintaining consistent electrical responses across ten cycles of alternating droplet measurements. This work presents a preclinical assessment approach, specifically for urine glucose monitoring, utilizing an innovative sensor based on the liquid–solid interface. The proposed concept has the potential to serve as an individual indicator for early medical symptom detection, offering relief to a large number of patients.
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ENHANCING ENERGY STORAGE PERFORMANCE OF BaTiO3/PDMS COMPOSITES WITH CNT FILLERS
(2025-01-01)
Sasipongpan, Apinya
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Rerngroen, Nakulkarn
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Vittayakorn, Wanwilai
This study explores the dielectric, energy storage, and piezoelectric properties of BaTiO3 (BT)/polydimethylsiloxane (PDMS) composites with varying BT concentrations (10-25 vol%) and an additional 1.5 vol% carbon nanotube (CNT) filler. Microstructural analysis confirmed the uniform distribution of BT nanoparticles, while phase characterization using XRD and FT-IR verified the presence of BT with no evidence of new bond formation. Dielectric measurements revealed a significant increase in the dielectric constant with higher BT content, reaching its peak in the 25 vol% BT/PDMS composite with CNTs. However, energy storage analysis showed that the 20 vol% BT/PDMS composite exhibited the highest energy density, indicating an optimal balance between dielectric constant and loss. The addition of CNTs did not significantly enhance energy storage performance due to their increased electrical conductivity, leakage currents, and agglomeration effects. Furthermore, piezoelectric measurements confirmed the piezoelectric behavior of the composites through an alternating voltage response under mechanical force. The CNT-filled composite exhibited a slightly lower voltage amplitude, likely due to charge dissipation and leakage. These results underscore the potential of BT/PDMS composites for flexible energy storage and piezoelectric applications, while also highlighting the limitations of CNT incorporation.
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DIELECTRIC AND FATIGUE LIFE ENHANCEMENT IN BaTiO3/Epoxy RESIN BASED COMPOSITES USED AS PIEZOELECTRIC NANOGENERATOR
(2025-01-01)
Vittayakorn, Wanwilai
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Rerngroen, Nakulkarn
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Sasipongpan, Apinya
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Muanghlua, Rangson
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Vittayakorn, Naratip
This study investigates the enhancement of dielectric properties and fatigue life in BaTiO3/epoxy resin composites utilized as the active material in piezoelectric nanogenerators. Through a systematic approach, various fabrication techniques and composite formulations are explored to optimize the dielectric constants, energy density, and piezoelectricity while mitigating fatigue-related degradation. The physical character, phase formation, and chemical properties of these composites are identified via the optical camera, XRD, and FTIR methods, respectively. The frequency dependence of dielectric properties for all samples is measured by an LCR meter. The hysteresis P-E loops are investigated in order to calculate the energy density and energy loss density of materials. The piezoelectric properties of these composites are performed by studying the generated output voltage and current after applying mechanical force to the samples. Moreover, MWCNT nanomaterials have also been incorporated into these composites in order to improve their dielectric value and fatigue life. The results show that the dielectric constant (εr) and dielectric loss (tanδ) of these composites are independent of frequency. After loading BaTiO3 into the epoxy resin matrix, the εr and tanδ significantly increased with the increasing BaTiO3 amount. The energy density and energy loss density of all composites were calculated from these P-E loops, and it is seen that pure epoxy resin shows the lowest energy density and energy loss density values. After loading BaTiO3 into the epoxy resin matrix, both the energy density and the energy loss density of the composites significantly increased. Moreover, after adding 20 percent by volume of BaTiO3 to the system, the energy density increases by 160% compared with pure epoxy resin. For the effect of MWCNT filler, it is seen that the εr, tanδ, energy density and energy loss density are significantly improved after adding 1.5 vol% of MWCNT into the system. The output current generated by applying mechanical force to the sample increased 27 times after adding MWCNT to the BT-filled epoxy resin composite. Finally, it can be concluded that all experimental results demonstrate significant enhancements in dielectric properties, energy density and electric output current, paving the way for the development of robust and efficient piezoelectric nanogenerators for diverse energy harvesting applications.
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FABRICATION OF BA5NB4O15 CERAMICS BY FLUX-ASSISTED ULTRA-LOW SINTERING TEMPERATURE TECHNIQUE
(2025-01-01)
Pulphol, Phieraya
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Teandam, Apichayaporn
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Charoonsuk, Thitirat
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Vittayakorn, Wanwilai
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Maluangnont, Tosapol
Ba<inf>5</inf>Nb<inf>4</inf>O<inf>15</inf> ceramic is a promising dielectric material for microwave frequencies. One of the factors that affects its dielectric properties is density, which can be controlled by fabrication processes such as sintering. Normally, conventional sintering requires high sintering temperature (T?> 1,200ºC) to produce grain coarsening and pore reduction which consumes high energy. However, there has been growing interest in low-temperature ceramic processing due to its potential to revolutionize the way ceramic materials are manufactured. Cold sintering is a new sintering technique that can be used to fabricate dense ceramics below 300°C. It can be applied to a variety of compounds, and the densification process is driven by the dissolution-precipitation mechanism, with the aid of a congruent solvent, pressure, and temperature. Herein, Ba<inf>5</inf>Nb<inf>4</inf>O<inf>15</inf> ceramics are prepared by cold sintering technique using hydrated barium hydroxide (Ba(OH)<inf>2</inf>-8H<inf>2</inf>O) as a flux to reduce sintering temperature and introduce densification process. The effects of processing parameters, including sintering temperature, dwelling time, pressure, and flux concentration, on the density and dielectric properties of sintered samples were investigated. Phase formation and electrical properties were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and an LCR meter. Under the sintering conditions T = 150°C, pressure = 7,000 kPa, and t = 60 min, the obtained Ba<inf>5</inf>Nb<inf>4</inf>O<inf>15</inf> ceramic exhibited a relative density of ˜80% which closes to the ceramics obtained from conventional sintering. These results suggest that sintering temperature has little influence on sample density, while applied pressure is the dominant factor in improving density. The mechanism of flux-assisted cold sintering and dielectric properties are also discussed.
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A Kirigami-Engineered “Skeletal Framework” Composite for Ultralow Hysteresis and Highly Stable Strain Sensors
(2025-11-24)
Pongampai, Satana
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Chaithaweep, Kanokwan
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Pakawanit, Phakkhananan
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Charoonsuk, Thitirat
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Bongkarn, Theerachai
Wearable strain sensors are pivotal for next-generation human–machine interfaces, yet achieving high fidelity, robustness, and sustainability in a single platform remains a significant challenge. A primary obstacle is the inherent viscoelasticity of soft materials, which leads to signal drift and hysteresis. Here, we report a highly stretchable and ultrastable strain sensor fabricated through a synergistic integration of Kirigami-based structural engineering and nanocomposite material design. By introducing titanium dioxide nanotubes (TNTs) into a bacterial cellulose (BC) matrix, we create a composite with a unique internal “skeletal framework”. This framework substantially reduces viscoelastic losses, resulting in an exceptionally low hysteresis of 0.6% and ensuring robust performance with 99.4% signal stability over >10 000 cycles. Concurrently, the Kirigami-patterned structure enhances stretchability to ∼235% while the framework amplifies sensitivity 5.8-fold. The practical viability of this high-fidelity sensor is demonstrated through the precise and repeatable control of a robotic arm, where ultralow hysteresis proves more critical than raw sensitivity. The sensor’s eco-friendly, water-based fabrication aligns high-fidelity sensing with sustainable processing, presenting a clear design paradigm for engineering reliable and eco-conscious wearable electronic devices.
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Process-structure-property relationships in low-temperature microwave dielectric ceramics: from glass-assisted sintering to cold sintering for 5G/6G devices
(2026-12-01)
Pulphol, Phieraya
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Tang, Ying
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Fang, Liang
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Vittayakorn, Wanwilai
;
Sukkha, Usa
With the rapid advancement of wireless communication from 5G to 6G, a pressing need has emerged for microwave dielectric ceramics with excellent performance at reduced processing temperatures, compatible with low-temperature co-fired ceramic technology. This review traces historical milestones and highlights modern design strategies for achieving optimum dielectric constant, ultra-low dielectric loss, and near-zero temperature coefficient of resonant frequency. Special emphasis is placed on recent advances in low-temperature densification routes, including sintering aids, intrinsically low-sintering-temperature ceramic families, and novel techniques like the cold sintering process. This review provides a critical analysis of the performance trade-offs inherent to each strategy, addressing the persistent challenges in achieving ultra-low loss. Furthermore, we highlight the paradigm shift toward a holistic, multifunctional design imperative for 6G systems. Finally, the transformative potential of cross-disciplinary approaches, particularly AI-assisted discovery, and computational modeling, is discussed as a key enabler for accelerating the design of next-generation, high-performance, and sustainable LTCC-compatible materials.
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Kinetic analysis of liquid–solid contact electrification: Using adsorption models as mechanistic probes for hybrid EDL behavior
(2026-08-01)
Chaithaweep, Kanokwan
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Pharino, Utchawadee
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Pongampai, Satana
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Sriphan, Saichon
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Charoonsuk, Thitirat
Liquid–solid interfaces are central to technologies ranging from energy storage to triboelectric nanogenerators (TENGs). Whereas classical electric double layer (EDL) theory describes these interfaces mainly in terms of electrostatic ion adsorption, hybrid EDL concepts suggest that interfacial electron transfer may also contribute importantly to charge generation. However, the hybrid EDL model has so far been discussed primarily at a qualitative level or through complex theoretical and computational treatments, and a simple, experimentally accessible macroscopic kinetic handle that can discriminate, in operando, between adsorption‑dominated and ET‑influenced regimes remains lacking. By analyzing high-resolution charging dynamics over systematically varied H₂SO₄ and HNO₃ concentrations, a clear concentration-dependent kinetic transition is identified. At low ionic strengths, the charging process is described more effectively by pseudo-second-order (PSO) kinetics, consistent with a reaction-influenced interfacial step, whereas at higher concentrations the system becomes pseudo-first-order (PFO) dominated, consistent with transport- and ion-screening-controlled behavior. Although previous studies have provided compelling theoretical and spectroscopic evidence that interfacial electron transfer contributes to liquid–solid contact electrification in TENGs, these mechanisms have rarely been examined through such simple macroscopic kinetic formalisms. In this work, classical adsorption kinetic models are used as operational probes for distinguishing electron-transfer-influenced regimes from ion-transport-dominated regimes at PTFE/liquid interfaces. The PSO-to-PFO crossover reported here is interpreted within the hybrid EDL framework as a kinetic marker of a transition from an electron-transfer-influenced charging regime at low concentration to an ion-transport- and screening-dominated regime at high concentration, thereby demonstrating how adsorption kinetics can serve as a practical diagnostic language for liquid–solid triboelectric systems.
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Cold sintering-assisted low temperature fabrication of dense Ba5Nb4O15 ceramics
(2026-06-08)
Sukkha, Usa
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Teandam, Apichayaporn
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Pakawanit, Phakkhananan
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Kamonpha, Phitsamai
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Vittayakorn, Wanwilai
This study presents a novel approach for fabricating Ba<inf>5</inf>Nb<inf>4</inf>O<inf>15</inf> (BNO) ceramics at low sintering temperatures via the cold sintering process (CSP), using Ba(OH)<inf>2</inf>·8H<inf>2</inf>O (BOH) as a transient liquid phase. CSP was performed under an external pressure of 10MPa with a sintering temperature range of 150°C to 300°C. Optimally, BNO-BOH ceramics achieved a relative density of 93.7 ± 0.43 when sintered at 250°C for 1h. Scanning electron microscopy (SEM) suggested that particle densification occurred via a dissolution-precipitation process, which filled pores and formed necks between particles. The study demonstrates that the residual liquid content is crucial for ceramic densification. Annealing the as-cold sintered BNO-BOH ceramics at 1000°C for 1h successfully eliminates the BaCO<inf>3</inf> secondary phase. Furthermore, dielectric properties of annealed ceramics were also characterized at room temperature from frequency range of 20Hz to 2MHz. The dielectric permittivity is reported to be 39.2 and 0.01 for tanδ at 1.8MHz. The cold sintering process provides an effective strategy to reduce the sintering temperature while achieving high relative density. This method offers a promising alternative for the fabrication of advanced ceramics.

Vittayakorn, Wanwilai

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