Vittayakorn, Naratip

Preferred name

Alternative Name

Vittayakorn, N.

Vittayakorn, Narathip

Main Affiliation

School of Science

naratip.vi@kmitl.ac.th

Now showing 1 - 10 of 72

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Mechanoluminescent-energy harvesting bimodal sensors for self-powered communication sensors
(2025-09-26)
Hajra, Sugato
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Panda, Swati
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Kaja, Kushal Ruthvik
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Song, Seongkyu
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Ryu, Yeonkyeong
Mechanoluminescence (ML) is the emission of light triggered by mechanical stress. In the meantime, accurate, quantitative force measurement is made possible by piezoelectricity, which transforms mechanical deformation into electrical signals. A deep insight into the mechanical interactions, such as strain-based phenomena, is achieved by integrating ML and piezoelectricity into a single device. In this study, a composite based on ZnS:Cu–polydimethylsiloxane (PDMS) is developed to achieve this dual functionality for ML-based optical responses and piezoelectric-based electrical output. The presence of piezoelectricity in PDMS–ZnS:Cu composites was traced using piezo force microscopy (PFM) imaging. Various mechanical stimuli of pressing, stretching, and bending are applied to evaluate the performance of the device. Under a force of 5 N, the piezoelectric nanogenerator (PENG) device generates a voltage of 17 V and a current of 70 nA. Additionally, ML and PENG effects are employed for underwater communications. A signal processing technique is further utilized for the classification of voltage signals produced during underwater communications. This self-powered dual-mode sensor has great potential for use in energy harvesting, wearable technology, and battery-free systems, opening the door to more intelligent and responsive user interfaces.
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Titanate Nanosheets/Cellulose Composite Showing Improved Crystallinity and Decreased Water Wettability by Gamma-Irradiation
(2025-11-25)
Tariwong, Yaowaluk
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Pulphol, Phieraya
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Sangtawesin, Tanagorn
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Seriwattanachai, Chaowaphat
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Kanjanaboos, Pongsakorn
While molecularly thin nanosheets have been increasingly studied as functional coatings, their use as a hydrophobic and γ-irradiation-tolerant component in biologically derived matrices is to be demonstrated. Herein, simple dip-coating was employed to fabricate titanate nanosheets/cellulose composites, which were subjected to γ-irradiation up to 50 kGy. Their surface chemistry was evaluated by water contact angle (WCA) measurements and X-ray photoelectron spectroscopy (XPS). Upon irradiation, the WCA of all samples nonmonotonically increased in three stages from ∼29 to 50° (noncoated) and ∼46 to 80° (composite, optimized at ∼1.2 wt %Ti loading, or 0.2 mg·cm–2). The titanium content and the 4+ valence did not change with the dose, suggesting the radiolytic stability. The dual surface modification occurs while cellulose fiber morphology and nanoscale mechanical properties are preserved. The increased WCA at the cellulose-part is explained by the γ-irradiation-induced crystallization according to the increased crystallinity index and improved thermal stability. At the other component, nanosheet coating results in increased surface roughness and diminished water–surface interactions. The latter is deduced from DSC measurements of water evaporation from pristine and 50 kGy-irradiated Cs<inf>0.7</inf>Ti<inf>1.825</inf>O<inf>4</inf>layered crystal-a nanosheet precursor. Our work suggests further exploration of nanosheets with diverse structures and compositions as coatings or fillers, which could find applications in γ-irradiation-sterilized barrier films.
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Calcium Copper Titanate Particles Based Energy Harvesting and Removal of Pharmaceutical Pollutants
(2025-05-13)
Kaja, Kushal Ruthvik
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Behera, Swayam Aryam
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Das, Bhagyashree
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Hajra, Sugato
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Panda, Swati
In this work, calcium copper titanate oxide (CaCu<inf>3</inf>Ti<inf>4</inf>O<inf>12</inf>, abbreviated as CCTO) was processed employing a solid-state reaction. The properties of CCTO were thoroughly characterized using various characterization tools. The CCTO particles layer and polytetrafluoroethylene (PTFE) acted as triboelectric layers, forming a contact and separation-based triboelectric nanogenerator (TENG). TENG, based on CCTO/PTFE, delivered an output of 74 V and 6 μA. TENG was utilized to harvest energy through various human activities, effectively charging capacitors, and was further attached to a pillow to monitor sleep. The study also evaluated the photocatalytic performance of CCTO for the degradation of doxycycline, achieving 87% efficiency within 45 minutes under visible light. The reaction pathway was thoroughly investigated, and catalyst reusability was examined. CCTO demonstrates potential as a dual-function material, serving both as a photocatalyst for environmental cleanup and as a triboelectric material for energy harvesting.
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The Y3+ Donor-Doped CCTO (Ca0.95Y0.05Cu3Ti4O12) Dielectric Fillers for Electrical Output Enhancement of Flexible Triboelectric Nanogenerator
(2026-06-03)
Saichompoo, Kittipan
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Rattanawongwiboon, Thitirat
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Kingkam, Wilasinee
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Pakawanit, Phakkhananan
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Sukkha, Usa
The escalating wearable electronic devices with their flexible energy sources demand has rendered the imperative scientific challenge on the development of materials for the flexible triboelectric nanogenerators (F-TENG), one of advanced energy harvesting systems. Dielectric material optimization, the Y3+ donor-doped calcium copper titanate based on exactly stoichiometric Ca<inf>0.95</inf>Y<inf>0.05</inf>Cu<inf>3</inf>Ti<inf>4</inf>O<inf>12</inf> (CCTYO), serves as a critical pathway in this work for achieving enhanced F-TENG via compositing with the polydimethylsiloxane (PDMS) polymer. The enhancement of electrical output has garnered substantial interest owing to its increased relative permittivity ((Formula presented.)). The influence of the loaded CCTYO amounts on structure, morphologies, dielectric properties, and electrical output, including open-circuit voltage (V<inf>OC</inf>), short-circuit current (I<inf>SC</inf>) and power density for PDMS/CCTYO composites is investigated. As compared with loading undoped CCTO, the additional Y3+ can improve higher F-TENG output by increasing the (Formula presented.) along with maintaining the loss tangent (tan δ < 0.02) at optimized condition. The appropriate amounts of CCTYO 0.75 wt% make the PDMS/CCTYO F-TENG to achieve V<inf>OC</inf> of ∼76.4 V (8.5 V/cm2) and I<inf>SC</inf> of ∼130.0 μA (14.4 μA/cm2), which were higher than pristine PDMS for 2.7 and 4.3 times. The power density of 53 µW/cm2 is 8.9 times higher than that of 6.3 µW/cm2 from the pristine PDMS. This study also provides a COMSOL multiphysics simulation, bridging laboratory experiments, for quantifying the triboelectric capability of dielectric materials.
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AC Electrical Properties of a NiFe-Layered Double Hydroxide with an Exceptionally Low Charge Density
(2025-05-08)
Maluangnont, Tosapol
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Sriphan, Saichon
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Chaithaweep, Kanokwan
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Vittayakorn, Naratip
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Wijitwongwan, Rattanawadee Ploy
Single-phase NiFe-layered double hydroxides (LDHs) with low and high charge densities [CD, 0.85 vs 3.23 nm-2; FeIII/(NiII + FeIII) = 0.05 and 0.25] were successfully prepared via urea-assisted coprecipitation in aqueous glycerol under hydrothermal conditions. The low-CD NiFe-LDH showed decreased apparent activation energies of water evaporation and of glycerol thermal decomposition, suggesting diminished intercalate/layer interactions relative to the high-CD one. The alternating current properties of the two samples were investigated on frequency and temperature domains by several formalisms that highlight distinct electrical components. We found that the low-CD NiFe-LDH exhibited smaller static dielectric permittivity and slower relaxation time, and it was less conducting than the high-CD analog. Complex plane analyses revealed the temperature dependence of resistance and capacitance at grain and grain boundary, varying by 7-10 orders of magnitude due to water loss and glycerol loss (∼9.5 and 11.3 wt %, respectively). Our work provides insights into intercalate dynamics in a low charge density LDH, which is difficult to obtain so far, from ambient to elevated temperatures (RT-250 °C) prior to decarbonation and layer collapse.
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PHASE FORMATION AND ELECTRICAL PROPERTIES OF BCLTS CERAMICS SYNTHESIZED VIA THE SOLID-STATE COMBUSTION TECHNIQUE
(2025-01-01)
Somsri, Widchaya
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Charoenthai, Nipaphat
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Sutthapintu, Aekkasit
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Noisak, Jitrawan
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Vittayakorn, Naratip
Lead-free Ba<inf>0.93</inf>Ca<inf>0.04</inf>La<inf>0.03</inf>Ti<inf>0.90</inf>Sn<inf>0.10</inf>O<inf>3</inf> (BCLTS) ceramics were fabricated via solid-state combustion technique. The BCLTS powders were calcined in a temperature range of 1075-1175°C for 2h and sintered in a temperature range of 1350-1450°C for 2h. The BCLTS powders exhibited a pure perovskite phase when calcined above 1150°C. All BCLTS ceramic samples displayed a perovskite structure with coexisting cubic and tetragonal phases, with a secondary phase observed only at 1450°C. The growth of grain size was increased with increasing sintering temperature (0.42 to 0.65 μm.). The highest dielectric and ferroelectric properties (ε<inf>r</inf>=3047, tan δ<inf>r</inf> = 0.029, P<inf>max</inf> = 9.52 μC/cm2, P<inf>r</inf> = 0.48 μC/cm2, E<inf>c</inf>= 1.04 kV/cm) were obtained at the sintering temperature of 1400°C. The altered phase structure in this research, compared to earlier studies, results in distinct outcomes for the dielectric and ferroelectric properties.
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Asymmetric dot-patterned wettable and antibacterial wound dressings from bacterial cellulose–alginate composites coated with stearic acid-modified ZnO/chitosan/AgNPs
(2025-01-01)
Ieamviteevanich, Pimchanok
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Onklam, Panida
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Kampechdee, Wariya
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Churiwan, Achana
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Vittayakorn, Naratip
To improve the wound dressing characteristics of bacterial cellulose-based materials and address the issue of asymmetric wound dressing with one hydrophilic side and another hydrophobic side, this study developed a new concept for the fabrication of an asymmetric wettable and antibacterial wound dressing by selective drop coating of stearic acid-modified ZnO, chitosan, and AgNPs to form a dot pattern on both surfaces of a bacterial cellulose–alginate composite (BA-ZnS/Ch/Ag). The coated surface was hydrophobic, with a WCA of 150° due to the formation of a low surface energy zinc stearate (C<inf>17</inf>H<inf>35</inf>COO)<inf>2</inf>Zn) monolayer on the ZnO particles and a high degree of hierarchical roughness. The asymmetric wettable BA-ZnS/Ch/Ag wound dressing maintained good water absorptivity (swelling rate 417%) and natural breathability (water vapor transmission rate 792 g.m−2 day−1) of the superhydrophilic bacterial cellulose-alginate composite that consisted of dense outer surfaces and porous inner layers and simultaneously possessed the superhydrophobic property of the coating area that can reduce the risk of infection from external fluids and improve the blood repellency and anti-adhesion properties. The BA-ZnS/Ch/Ag wound dressing showed good antibacterial activity against S. aureus and E. coli and non-toxicity to human keratinocyte immortal cells (HaCaT), making it suitable for clinical applications.
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Boosting sustainable hydrogen production via water splitting and urea oxidation using spinel hollow-sphere nano catalysts
(2025-10-01)
Lin, Hsin Yu
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Vasu, Dhanapal
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Tsang, Chun Han
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Hsu, Cheng Shan
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Prashanth, Gopi
In this study, spinel MgCo<inf>2</inf>O<inf>4</inf> materials were synthesized using three different techniques: freeze-drying, solid-state, and hydrothermal methods, to evaluate their structural, morphological, and electrocatalytic properties. Comprehensive characterization techniques including XRD, Raman spectroscopy, FT-IR, FESEM, HRTEM, and XPS confirmed the successful formation of phase-pure MgCo<inf>2</inf>O<inf>4</inf> with varied morphologies. Among the synthesized materials, the freeze-dried sample exhibited a well-defined hollow-sphere structure, providing abundant electroactive sites and superior electron/mass transport pathways. This morphology contributed to outstanding electrocatalytic performance. For the oxygen evolution reaction (OER), the hollow-sphere MgCo<inf>2</inf>O<inf>4</inf> catalyst demonstrated a low overpotential of 430 mV at 10 mA cm−2 and a Tafel slope of 190 mV dec−1. In addition, the same catalyst exhibited excellent activity for the urea oxidation reaction (UOR), with a Tafel slope of 95 mV dec−1 and enhanced current density under alkaline conditions. The superior UOR activity, enabled by the lower oxidation potential of urea (∼0.37 V vs. RHE), also highlights its potential for energy-efficient hydrogen production and wastewater treatment. This work establishes a scalable and cost-effective strategy to synthesize high-performance MgCo<inf>2</inf>O<inf>4</inf> hollow-sphere electrocatalysts, paving the way for their application in sustainable energy and environmental technologies.
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Advances in nanogenerator enabled smart mask-based self-powered health monitoring units
(2025-11-21)
Belal, Mohamed A.
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Panda, Swati
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Khanapuram, Udaykumar
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Hajra, Sugato
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Kaja, Kushal Ruthvik
The detection and analysis of volatile biomarkers in exhaled breath have emerged as promising non-invasive strategies for early disease diagnosis, therapeutic monitoring, and personalized healthcare. Traditional gas sensing platforms, however, often face limitations including dependency on external power sources, bulky designs, and inadequate sensitivity or selectivity under physiological conditions. This work provides a complete overview of recent improvements in self-powered gas sensors, with a special emphasis on their use in exhaled breath analysis for health monitoring. We begin by discussing the biomedical importance of breath-based diagnostics and the significant challenges associated with traditional sensor technology. Afterward, we investigate the mechanisms of energy harvesting systems such as triboelectric nanogenerators (TENGs) and piezoelectric nanogenerators (PENGs), which facilitate the self-powered operation without an external energy supply. Innovations in materials, structural design techniques, and integration strategies that improve mechanical flexibility, sensitivity, and gas selectivity are highlighted. We also highlight recent breakthroughs in wearable and portable gas sensing platforms that demonstrate real-time responsiveness and human-interfaced compatibility. Despite significant progress, challenges such as miniaturization, biomarker specificity, signal stability in dynamic environments, and large-scale manufacturability still need to be addressed. Finally, we discuss potential ways to address these barriers, envisioning a future where self-powered gas sensors play a transformative role in point-of-care diagnostics, continuous health monitoring, and smart healthcare ecosystems. This review aims to serve as a valuable resource for researchers and developers seeking to advance the field of self-powered biomedical sensing technologies.
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Synergistic Piezo- and Triboelectricity in a Novel Triglycine Sulfate/Bacterial Cellulose/Chitosan Flexible Composite Nanogenerator
(2025-08-14)
Ukasi, Sirinya
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Saichompoo, Kittipan
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Sae-tang, Chanachot
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Pakawanit, Phakkhananan
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Pongampai, Satana
Organic piezoelectric materials offer sustainable alternatives for mechanical energy harvesting (MEH), yet their potential remains underexplored compared to inorganic counterparts. This study pioneers the use of triglycine sulfate (TGS), a rarely studied organic piezoelectric, within a flexible three-phase composite with bacterial cellulose (BC) and chitosan (CS) for piezoelectric (PENG) and triboelectric (TENG) nanogenerators. Unlike widely researched systems, TGS's unique hybrid organic–inorganic nature is leveraged here for the first time in MEH. Optimized at a 50:50 BC:CS ratio with 40 wt.% TGS, achieves a TENG output of 141.2 V and 93.3 µA post-poling—1.8 and 2.4 fold higher than unpoled samples—driven by TGS's dipole alignment. Separately, the configuration utilizing a 5 wt.% TGS loading yields 13.7 V and 0.19 µA. Advanced characterization (ATR-FTIR, SR-XTM) and simulations (COMSOL, DFT) reveal TGS's synergy with BC/CS roughness, enhancing charge generation. Delivering 118.65 µW cm−2, the TENG (from the 40 wt.% TGS poled sample) powers a digital watch, showcasing practical promise. This work not only introduces TGS as a novel MEH candidate but also provides mechanistic insights into its polarization, advancing bio-hybrid nanogenerator design.

Vittayakorn, Naratip

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