IEEE Journal on Flexible Electronics最新文献

{"title":"Advances in Organic Thin-Film Transistor Technology for Flexible Analog Front Ends in Wearable Electronics","authors":"Zikang Mei;Li’ang Deng;Botian Huang;Wei Tang;Xiaojun Guo","doi":"10.1109/JFLEX.2025.3528904","DOIUrl":"https://doi.org/10.1109/JFLEX.2025.3528904","url":null,"abstract":"Recent developments in health monitoring applications have heightened the need for wearable devices to acquire human bio-electrical and bio-chemical signals. To realize sampling of these signals, it is urgent to develop highly customizable analog front ends that meet diverse processing and performance requirements such as low-cost manufacturing, unique form factor for flexibility, and accurate acquisition of signal under strict power constraint. Organic thin-film transistor (OTFT), owning superior mechanical flexibility and feasibility of being manufactured on arbitrary plastics, is regarded as a promising technology platform for developing such customized front ends. This article gives a brief overview of the recent development of OTFT-based analog front ends applied in wearable electronics. The key performance indicators of state-of-the-art OTFTs, including sub-60-mV/dec switching, high transconductance efficiency of 38.7 S/A, and operation at 1 V, are presented, highlighting their potential for application in flexible and wearable electronics. The commonly used device structures, material stacks, and manufacturing strategies for flexible low-voltage device technology are first discussed. Efforts devoted to OTFT-based analog front-end circuits and systems, including amplifier, analog-to-digital converter (ADC), and power management circuit, are then introduced. Finally, the remaining challenges to address for future development of advanced OTFT front ends are clarified. This article will provide guidelines for the processing and design of flexible OTFT analog front end for wearable electronics.","PeriodicalId":100623,"journal":{"name":"IEEE Journal on Flexible Electronics","volume":"3 11","pages":"508-521"},"PeriodicalIF":0.0,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143521537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Directed Assembly of p-Type Tellurium Nanowires for Room-Temperature-Processed Thin-Film Transistors","authors":"Mohammed Hadhi Pazhaya Puthanveettil;Manvendra Singh;Siri Chandana Amarakonda;Subho Dasgupta","doi":"10.1109/JFLEX.2025.3526083","DOIUrl":"https://doi.org/10.1109/JFLEX.2025.3526083","url":null,"abstract":"The flexible electronics domain has emerged as an alternate technology beyond silicon CMOS because of advancements in low-temperature solution-processable thin-film transistors (TFTs) and circuits. However, uniformity and scalability remain the main hindrances for solution-processed devices, especially when it comes to the deposition of nanomaterials. In this regard, directional assembly using dielectrophoresis is a quick and easy way to uniformly align 1-D nanostructures, for example, nanowires, to bridge a gap between the electrodes to form a transistor channel using nonlinear ac electric fields. In this study, high-hole mobility tellurium nanowires are assembled using nonlinear ac dielectrophoresis to fabricate electrolyte-gated TFTs (EG-TFTs) on a flexible substrate at room temperature. These p-type flexible transistors exhibit an on-off ratio of <inline-formula> <tex-math>$3.3times 10^{2}$ </tex-math></inline-formula>, an ON-current density of 20 <inline-formula> <tex-math>$mu $ </tex-math></inline-formula>A <inline-formula> <tex-math>$mu $ </tex-math></inline-formula>m−1, a specific transconductance of 8.5 <inline-formula> <tex-math>$mu $ </tex-math></inline-formula>S <inline-formula> <tex-math>$mu $ </tex-math></inline-formula>m−1, and linear mobility of 20.6 cm2 V−1 s−1 with adequate mechanical strain tolerance.","PeriodicalId":100623,"journal":{"name":"IEEE Journal on Flexible Electronics","volume":"3 10","pages":"454-460"},"PeriodicalIF":0.0,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flexible Low-Power Digital Circuits With Unipolar Amorphous Silicon Thin-Film Transistors","authors":"Shubham Ranjan;Sparsh Kapar;Czang-Ho Lee;William S. Wong;Manoj Sachdev","doi":"10.1109/JFLEX.2025.3525598","DOIUrl":"https://doi.org/10.1109/JFLEX.2025.3525598","url":null,"abstract":"Thin-film transistor (TFT) technology has demonstrated its effectiveness in large-area cost-efficient applications such as displays, flexible electronics, and medical devices. However, TFTs are typically unipolar in nature, and therefore, the realization of CMOS-like digital circuits is challenging. Traditional methods for implementing logic gates and complex circuits with unipolar TFT devices lead to high static power consumption and limited output swing. While various mitigation techniques have been developed, they fail to eliminate the direct path current problem in these circuits, which hinders static power reduction. The objective of this study is to address these issues and study its effect on flexible substrate. In this article, we propose logic gates that address these issues using a half-latch circuit. To demonstrate the concept, a 3-to-8 decoder was built using only n-type amorphous silicon (a-Si:H) TFTs on both glass and flexible substrates. We analyzed the impact of bending and substrate materials on the design. It was observed that the TFTs show an increase in current up to 8% under tensile stress, while a decrease in current up to 4% under compressive stress on flexible substrate. Measurements indicate that the proposed design reduces the average total power consumption of the 3-to-8 decoder by 46.5% compared with state-of-the-art techniques under various conditions.","PeriodicalId":100623,"journal":{"name":"IEEE Journal on Flexible Electronics","volume":"3 12","pages":"533-543"},"PeriodicalIF":0.0,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Unified Physics-Based Model for Analyzing Hysteresis in Organic Thin-Film Transistors","authors":"Amer Zaibi;Ahmed Mounir Abdelmoneam;Patryk Golec;Magali Estrada;Antonio Cerdeira;Lina Kadura;Laurie E. Calvet;Benjamin Iñiguez","doi":"10.1109/JFLEX.2024.3523866","DOIUrl":"https://doi.org/10.1109/JFLEX.2024.3523866","url":null,"abstract":"Hysteresis effects are often observed in voltage sweeps of organic thin-film transistors (OTFTs), resulting in threshold voltage shifts. While commonly associated with bias stress effects, the origins of hysteresis are diverse, with limited scientific studies providing a complete understanding of hysteresis in OFETs. Here, we use a physics-based model for organic thin film to investigate the hysteresis effects in OTFTS. Unlike many previous studies, our model allows for a more in-depth investigation of this phenomenon. Our method demonstrates a strong agreement between measurement and the model using parameter values obtained through the extraction process given by the unified modeling and extraction method (UMEM). In our quantitative analysis, we examined the hysteresis behavior in transistors of different channel lengths. For a transistor with a channel length of <inline-formula> <tex-math>$200~mu $ </tex-math></inline-formula> m, the threshold voltage shift (<inline-formula> <tex-math>$Delta {V} _{mathrm {T}}$ </tex-math></inline-formula>) between backward and forward sweeps was 0.15 V. In contrast, for a transistor with a channel length of <inline-formula> <tex-math>$5~mu $ </tex-math></inline-formula> m, <inline-formula> <tex-math>$Delta {V} _{mathrm {T}}$ </tex-math></inline-formula> was observed to be 0.3 V. In addition, we observed that the characteristics temperature (<inline-formula> <tex-math>$T_{0}$ </tex-math></inline-formula>) of the density of states (DOSs) increases, which impacts the trapping behavior.","PeriodicalId":100623,"journal":{"name":"IEEE Journal on Flexible Electronics","volume":"3 11","pages":"502-507"},"PeriodicalIF":0.0,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143521370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"IEEE Journal on Flexible Electronics Publication Information","authors":"","doi":"10.1109/JFLEX.2024.3503029","DOIUrl":"https://doi.org/10.1109/JFLEX.2024.3503029","url":null,"abstract":"","PeriodicalId":100623,"journal":{"name":"IEEE Journal on Flexible Electronics","volume":"3 9","pages":"C2-C2"},"PeriodicalIF":0.0,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10805790","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142844234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"IEEE Journal on Flexible Electronics Call for Papers: Special Issue on Selected Papers from the 6th IEEE International Flexible Electronics Technology Conference (IFETC) 2024","authors":"","doi":"10.1109/JFLEX.2024.3515772","DOIUrl":"https://doi.org/10.1109/JFLEX.2024.3515772","url":null,"abstract":"","PeriodicalId":100623,"journal":{"name":"IEEE Journal on Flexible Electronics","volume":"3 9","pages":"434-434"},"PeriodicalIF":0.0,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10805789","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142844236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of Self-Powered e-Gear Selector Based on Single-Electrode Triboelectric Nanogenerator (TENG) Technology","authors":"Sam Ali;Dinesh Maddipatla;Bradley J. Bazuin;Massood Z. Atashbar","doi":"10.1109/JFLEX.2024.3515919","DOIUrl":"https://doi.org/10.1109/JFLEX.2024.3515919","url":null,"abstract":"A novel e-Gear selector single-electrode-based triboelectric nanogenerator (TENG) was successfully designed, fabricated, and tested on flexible substrates. The proposed device consists of four TENG sensors representing the traditional gear shift selector (P, R, N, and D). Leather, cotton, paper, and thermoplastic polyurethane (TPU) were selected as bottom triboelectric layers for TENGs 1–4, respectively. Silver (Ag) ink was screen-printed on the backside of each layer representing the single electrode. Human skin was chosen as the top triboelectric layer. Based on the selection of the materials, each TENG device generates different output voltages, enabling the selection of the intended gear mode without the need for a complex control algorithm. The TENG device was characterized in terms of open-circuit voltage (<inline-formula> <tex-math>${V} _{text {oc}}$ </tex-math></inline-formula>) and short-circuit current (<inline-formula> <tex-math>${I} _{text {sc}}$ </tex-math></inline-formula>). The repeatability and reproducibility of the TENG device were evaluated by fabricating three samples of each TENG device and by testing each TENG device three times. An average <inline-formula> <tex-math>${V} _{text {oc}}$ </tex-math></inline-formula> of <inline-formula> <tex-math>$4.27~pm ~0.36$ </tex-math></inline-formula>, <inline-formula> <tex-math>$7~pm ~0.31$ </tex-math></inline-formula>, <inline-formula> <tex-math>$9.05~pm ~0.21$ </tex-math></inline-formula>, and <inline-formula> <tex-math>$12.38~pm ~0.34$ </tex-math></inline-formula> Vpp, resulted in a power density of <inline-formula> <tex-math>$0.37~pm ~0.05$ </tex-math></inline-formula>, <inline-formula> <tex-math>$0.72~pm ~0.09$ </tex-math></inline-formula>, <inline-formula> <tex-math>$0.95~pm ~0.07$ </tex-math></inline-formula>, and <inline-formula> <tex-math>$1.74~pm ~0.10~mu $ </tex-math></inline-formula>W/cm2, was measured for TENGs 1–4, respectively. The performance of the e-Gear selector showcased the potential of the TENG energy harvesting method for integration into the automotive industry, aligning with the rapid advancements in electric vehicle (EV) applications. This technology is particularly promising for future gear selector designs, as it eliminates the need for external power supplies, reduces cost, minimizes wiring, and offers greater flexibility in positioning within the vehicle.","PeriodicalId":100623,"journal":{"name":"IEEE Journal on Flexible Electronics","volume":"4 1","pages":"20-29"},"PeriodicalIF":0.0,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143875102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fabricating X-Band Frequency Selective Surface on Glass Fabric by Screen Printing Method","authors":"Tugce Altuntop Ersan;Ozgur Birer;Akin Dalkilic;Mehmet Erim Inal;Arcan F. Dericioglu","doi":"10.1109/JFLEX.2024.3513913","DOIUrl":"https://doi.org/10.1109/JFLEX.2024.3513913","url":null,"abstract":"Frequency selective surfaces (FSSs), periodic metallic patterns on radiotransparent materials, are used to decrease radar cross section (RCS) of a radiating structure by allowing the transmittance of signals of the desired frequency band(s). A particular surface of interest is the glass fiber woven fabric which is used to manufacture polymer composite radomes. It is particularly challenging to pattern such surfaces due to inherent topography and problems regarding handling of glass fabric. This study presents modeling and manufacturing of X-band (8–12 GHz) FSS patterns on glass fabric substrate, using commercially available silver-based paste applied by the optimized screen-printing method. FSS patterns containing crossed dipole unit cells showing bandpass behavior at X-band were printed on 110 GSM (g/m2) plain weave glass fabric substrates using two different conductive pastes Type-1 (micro) and Type-2 (micro and nano) with different size distributions. Electromagnetic (EM) performances of both samples were measured using free space method and compared with each other as well as with simulation results. Experiments showed that due to the porous-like (perforated) structure of the glass fabric, accumulation characteristics of these pastes on the substrate surface are different from each other, and printed FSS layers exhibit different EM performances. As the Type-1 paste with relatively large conductive particles accumulated on the surface of the glass fabric with limited interpenetration into the fiber bundles, it acted as a continuous conductive surface which provided almost fully matching reflection and transmission characteristics with that of the simulation. In contrast, Type-2 paste with smaller conductive particles penetrated the bundles forming a partially discontinuous conductive pattern, which resulted in deviation from the expected EM behavior. Consequently, by selecting a suitable off-the-shelf conductive paste with proper characteristics for the substrate material, FSS layer with desired EM performance can be manufactured via screen-printing process without need of cumbersome surface modification.","PeriodicalId":100623,"journal":{"name":"IEEE Journal on Flexible Electronics","volume":"3 12","pages":"544-551"},"PeriodicalIF":0.0,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solution Processable Barrier Films Using a Filled Polymer to Encapsulate Flexible Printed Electronics","authors":"Zehua Chen;Ulrich Gengenbach;Shant Gananian;Daniel Moser;Klaus-Martin Reichert;Liyu Huang;Liane Koker","doi":"10.1109/JFLEX.2024.3512473","DOIUrl":"https://doi.org/10.1109/JFLEX.2024.3512473","url":null,"abstract":"Flexible printed electronics (FPEs) are gaining attention due to their diverse applications, including smart packaging and medical and wearable devices. A key aspect in ensuring the longevity and functionality of FPE devices is their encapsulation, which shields them from adverse environmental factors such as humidity and oxygen. One promising approach to achieve this is solution-processed encapsulation, where fillers are added to a polymer matrix to form barrier films. In this work, glass flakes (GFs), graphene oxide (GO), montmorillonite (MMT), and silica are investigated as possible fillers in poly(vinyl alcohol) (PVA). The barrier films are fabricated by doctor blading. To select the most effective filler type, a water vapor transmission rate (WVTR) test method based on an adapted desiccant method from the ASTM E96/E96M-22 standard is developed. The optimal filler concentration in PVA is also determined. The fabricated barrier films are optically inspected. Moreover, the barrier effect of selected PVA/filler films is validated by resistance measurements of inkjet-printed silver tracks subjected to damp heat and room storage conditions.","PeriodicalId":100623,"journal":{"name":"IEEE Journal on Flexible Electronics","volume":"4 1","pages":"4-11"},"PeriodicalIF":0.0,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10778432","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143875167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Roll-to-Roll Screen-Printed Monolithic Supercapacitors and Modules With Varying Electrode Areas","authors":"Timo Punkari;Aapo Kattainen;Alexandre Fonseca;Joana Pronto;Jari Keskinen;Matti Mäntysalo","doi":"10.1109/JFLEX.2024.3510216","DOIUrl":"https://doi.org/10.1109/JFLEX.2024.3510216","url":null,"abstract":"Monolithic supercapacitors (SCs) were fabricated using roll-to-roll (R2R) screen printing. The printing process was utilized for various layouts, in which the electrode area was changed for different SC cells and modules. A common fabrication method for SCs is to assemble stacked structure by different layers. Another fabrication method requires a planar interdigitated electrode (IDE) structure, in which the SC can be fully printed on a single substrate. However, a more novel approach is to use a monolithic structure, which represents a stacked structure. The monolithic SC is printed layer-by-layer on a single substrate but is not restricted to the IDE structure enabling larger capacitance and lower equivalent series resistance (ESR). In this work, the monolithic SCs were successfully fabricated from R2R by screen printing. The printed SCs include individual cells and modules with cells in series. All SCs had varying electrode areas to achieve different capacitances and to determine if the area affects to the yield. The smaller area was observed to better prevent the contact through the separator. However, the modules had more variation in the cells, even with smaller electrode areas.","PeriodicalId":100623,"journal":{"name":"IEEE Journal on Flexible Electronics","volume":"4 1","pages":"12-19"},"PeriodicalIF":0.0,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10772224","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143875235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}