Review
Chemistry, Multidisciplinary
Anjum Qureshi, Javed H. Niazi
Summary: Flexible and stretchable wearable electronic devices have been developed using graphene nanostructures and flexible substrates for non-invasive health monitoring applications, particularly in monitoring sweat biomarkers such as glucose. These devices have improved sensitivity, electronic readouts, signal conditioning, energy harvesting, and graphene surface modification. Various methods, including photolithography and ink printing, have been employed for the fabrication of conductive and stretchable micro-nano electrodes. The review explores the potential of graphene-interfaced wearable devices for non-invasive health monitoring.
MATERIALS HORIZONS
(2023)
Article
Engineering, Electrical & Electronic
Shilin Lu, Tianchun Nie, Yang Li, Yuanyue Li, Zhao Yao, Nam Young Kim, Shandong Li
Summary: In this study, the sensitivity of a capacitive pressure sensor was improved by optimizing the geometry of the laser-scribed graphene (LSG) electrodes. The sensor demonstrated high sensitivity, fast response/recovery time, low detection limit, and excellent mechanical stability. The research shows the potential of inter-comb structured LSG electrodes in highly sensitive flexible pressure sensors.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
Mst Moriom Rojy Momota, Bashir I. Morshed, Tamanna Ferdous, Tomoko Fujiwara
Summary: In this study, flexible dry ECG electrodes of different shapes and sizes were developed using inkjet printing technology. Compared to commercial gel electrodes, inkjet printing electrodes have a longer lifetime and lower noise. Inkjet printing allows for personalized shape and size customization of the electrodes through additive manufacturing.
IEEE SENSORS JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Peng Li, Qiaoyan Hao, Jidong Liu, Dianyu Qi, Haibo Gan, Jiaqi Zhu, Fei Liu, Zijian Zheng, Wenjing Zhang
Summary: This paper presents a full-solution process for fabricating copper (Cu) electrodes on polymeric substrates, demonstrating low fabrication costs, superior mechanical durability, and the potential for constructing flexible electronic devices.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Review
Chemistry, Multidisciplinary
Lili Meng, Wei Wang, Bojie Xu, Ji Qin, Kejie Zhang, Huan Liu
Summary: Flexible transparent electrodes (FTEs) have been widely utilized in printable electronic devices, especially those involving light. Solution processes offer advantages in preparing FTEs due to their mild operation conditions, high-throughput, and diversity in micropatterning conductive nanomaterials. The performance of FTEs is determined by the solutions capable of micropatterning conductive nanomaterials, the substrates used, and their applications in flexible electronics. This review provides inspiration for developing functional FTEs.
Article
Chemistry, Multidisciplinary
Rui Wang, Xiaoyang Zhu, Luanfa Sun, Shuai Shang, Hongke Li, Wensong Ge, Hongbo Lan
Summary: A novel flexible strain sensor with high sensitivity and transparency was developed by filling a multiwalled carbon nanotube solution into polydimethylsiloxane channel films. The fabricated sensor showed superior gauge factors, good stability, and durability for monitoring various human movements.
Article
Biotechnology & Applied Microbiology
Daiki Ando, Tetsuhiko F. Teshima, Francisco Zurita, Hu Peng, Kota Ogura, Kenji Kondo, Lennart Weiss, Ayumi Hirano-Iwata, Markus Becherer, Joe Alexander, Bernhard Wolfrum
Summary: The increasing demand for bioelectronics has led to the development of materials that can bridge the gap between electronic devices and biological tissues. Biopolymers have gained attention as next-generation materials for bioelectronics due to their high biocompatibility, biodegradability, and sustainability. However, their use has been limited by the compatibility issues with traditional fabrication methods. This study presents a fabrication process for chitosan nanofiber films integrated with conductive materials, providing a potential solution for future bioelectronic devices based on biopolymer nanofibers.
JOURNAL OF NANOBIOTECHNOLOGY
(2022)
Article
Nanoscience & Nanotechnology
Xiaoke Ding, Md Fazlay Rubby, Suya Que, Sajid Uchayash, Long Que
Summary: We present a method for fabricating silicon micro-nanostructures of various shapes by manipulating the number and size of self-assembled polystyrene beads as a mask and adjusting the reactive ion etching time. This approach offers a simple, scalable, and cost-effective solution without requiring sophisticated nanomanufacturing equipment. The demonstration of this method includes the fabrication of silicon micro- or nanoflowers, micro- or nanobells, nanopyramids, and nanotriangles using polystyrene beads as a mask, as well as the creation of flexible micro- nanostructures using silicon molds. Furthermore, we showcase the fabrication of bandage-type electrochemical sensors for detecting dopamine in artificial sweat, indicating the potential of this method for developing wearable micro-nanostructure-enabled sensors.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Engineering, Electrical & Electronic
Wenzhen Yang, Yu Liu, Wei Xu, Heng-Yong Nie
Summary: The flexible capacitive pressure transducer is a critical soft electronics in wearable consumables and e-skins due to its high sensitivity, mechanical robustness, lightweight, and wearability. The introduction of interfacial microstructure enhances pressure sensitivity, with a new methodology used to fabricate the sensors with optimized copper-plated polyimide electrodes and porous polydimethylsiloxane layer. The impact of geometric complexity on sensitivity, repeatability, and reliability is examined, with a robotic gripper showcasing the ability to control force on soft targets.
IEEE SENSORS JOURNAL
(2021)
Article
Nanoscience & Nanotechnology
Hsiang-Yen Liu, Wei-Ya Su, Che-Jia Chang, Shih-Yen Lin, Chun-Yuan Huang
Summary: With the help of vdW epitaxy, nanometer-thick and highly conductive gold films are deposited onto MoS2 surfaces as transparent anode electrodes for QLEDs. The Au film exhibits excellent tensile bending stability and can replace current ITO anode electrodes for flexible device applications.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Xue Wang, Pengfei Zhao, Yanhong Tong, Shanlei Guo, Guodong Zhao, Mingxin Zhang, Hongyan Yu, Xiaoli Zhao, Qingxin Tang, Yichun Liu
Summary: By inserting a PEDOT: PSS layer onto the rGO electrode, high-conductive transparent and flexible electrodes can be fabricated, which exhibit high precision, high transparency, and good adherence. The resulting organic transistor array shows enhanced modulation effect, increased electron mobility, and stable operation on human skin.
ADVANCED MATERIALS TECHNOLOGIES
(2022)
Article
Materials Science, Multidisciplinary
Xiaohui Fang, Lizhen Min, Zhen Qin, Shun Gong, Biao Zhao, Yuhuan Lv, Kai Pan
Summary: A flexible and wearable pressure sensor based on pyramid-like MXene film is designed and prepared, showing high stability and promising application potential in human motion and health monitoring. The sensor can output continuous and stable electrical signal under stress thanks to its conical pyramid structure, and demonstrates good cycling stability and long working life. It exhibits high sensitivity and a wide sensing range under small stress, with short response and recovery time. The sensing mechanism of the pressure sensor is explored.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Review
Chemistry, Multidisciplinary
Tian-Run Lv, Wen-Hai Zhang, Ya-Qiong Yang, Jia-Chen Zhang, Ming-Jie Yin, Zhigang Yin, Ken-Tye Yong, Quan-Fu An
Summary: With increasing demands for flexible organic electronic devices, conductive polymers have shown significant breakthroughs in the past decade due to their outstanding conductivity, solution-processing ability, and tailorability. However, commercialization of these devices still lags behind due to performance limitations and limited manufacturing techniques. This review comprehensively summarizes the state-of-the-art technologies for developing organic devices using conductive polymers, including synthesis methods, film fabrication techniques, nanostructure and microstructure tailoring, device applications, and future directions.
Article
Chemistry, Multidisciplinary
Seokyeong Lee, Eui Hyuk Kim, Seunggun Yu, Hyerim Kim, Chanho Park, Seung Won Lee, Hyowon Han, Wookyoung Jin, Kyuho Lee, Chang Eun Lee, Jihye Jang, Chong Min Koo, Cheolmin Park
Summary: Transparent and flexible MXene electronic devices have been demonstrated by laminating a thin polymer film onto a solution-processed MXene layer, providing high environmental stability even under prolonged air exposure at high temperatures and humidity levels. The resulting polymer-laminated (PL) MXene electrode enables the development of field-driven photoelectronic devices with high transparency and mechanical flexibility, showcasing applications in electroluminescent displays, pressure sensors, and nanogenerators for sensing and energy harvesting.
Article
Materials Science, Multidisciplinary
Jianfeng Zhang, Bin Wei, Lin Wang, Xuyong Yang
Summary: Metal halide perovskite light-emitting diodes (PeLEDs) are considered promising candidates for next-generation high-resolution displays due to their excellent properties. However, their performance is limited by the sensitivity of perovskites to solvents. All-solution-processed deposition methods have the potential to reduce costs and improve production efficiency.
JOURNAL OF MATERIALS CHEMISTRY C
(2021)
Article
Chemistry, Multidisciplinary
Ayaka Sato, Yuya Ikeda, Koichi Yamaguchi, Varun Vohra
Article
Chemistry, Multidisciplinary
Varun Vohra
Article
Chemistry, Multidisciplinary
Varun Vohra, Takayuki Uchiyama, Shusei Inaba, Yoshiko Okada-Shudo
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2019)
Article
Materials Science, Multidisciplinary
Takahiro Takumi, Savanna Lloyd, Hideyuki Murata, Varun Vohra
MATERIALS RESEARCH LETTERS
(2019)
Article
Nanoscience & Nanotechnology
Shusei Inaba, Ryosuke Arai, Geanina Mihai, Oana Lazar, Calin Moise, Marius Enachescu, Yuko Takeoka, Varun Vohra
ACS APPLIED MATERIALS & INTERFACES
(2019)
Article
Chemistry, Physical
Newayemedhin A. Tegegne, Zelalem Abdissa, Wendimagegn Mammo, Takayuki Uchiyama, Yoshiko Okada-Shudo, Francesco Galeotti, William Porzio, Mats R. Andersson, Derck Schlettwein, Varun Vohra, Heinrich Schwoerer
JOURNAL OF PHYSICAL CHEMISTRY C
(2020)
Article
Chemistry, Multidisciplinary
Tomoaki Takada, Takayuki Uchiyama, Yoshiko Okada-Shudo, Katsuhito Hoshino, Ko Koizumi, Yuko Takeoka, Varun Vohra
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2020)
Article
Materials Science, Multidisciplinary
Varun Vohra, Shunsuke Shimizu, Yuko Takeoka
Article
Energy & Fuels
Popoti J. Maake, Amogelang S. Bolokang, Christopher J. Arendse, Varun Vohra, Emmanuel I. Iwuoha, David E. Motaung
Article
Chemistry, Multidisciplinary
Varun Vohra, Yumi Matsunaga, Tomoaki Takada, Ayumu Kiyokawa, Luisa Barba, William Porzio
Summary: The study compared the performances and stability of different active layers in organic solar cells using different electron acceptors. It was found that PC71BM molecules have higher resistance to oxidation compared to nonfullerene acceptors. Polymer active layers can create durable OSCs if oxidation of the polymer acceptors can be avoided.
Article
Chemistry, Multidisciplinary
Anna Maria Ferretti, Marianna Diterlizzi, William Porzio, Umberto Giovanella, Lucia Ganzer, Tersilla Virgili, Varun Vohra, Eduardo Arias, Ivana Moggio, Guido Scavia, Silvia Destri, Stefania Zappia
Summary: The use of water-processable nanoparticles (WPNPs) is a promising strategy for processing organic semiconducting materials into aqueous medium. In this study, the effects of chemical structure and length of hydrophilic coil blocks in amphiphilic rod-coil block copolymers (BCPs) on the nanomorphology of active materials and device performances were investigated.
Article
Chemistry, Physical
Lucia Ganzer, Stefania Zappia, Mattia Russo, Anna Maria Ferretti, Varun Vohra, Marianna Diterlizzi, Maria Rosa Antognazza, Silvia Destri, Tersilla Virgili
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2020)
Article
Chemistry, Multidisciplinary
Mohd Zaidan Abdul Aziz, Koichi Higashimine, Nobutaka Shioya, Takafumi Shimoaka, Takeshi Hasegawa, Heisuke Sakai, Varun Vohra, Hideyuki Murata
Article
Materials Science, Multidisciplinary
Takayuki Uchiyama, Takashi Sano, Yoshiko Okada-Shudo, Varun Vohra
JOURNAL OF MATERIALS CHEMISTRY C
(2020)
Article
Chemistry, Physical
Takashi Sano, Shusei Inaba, Varun Vohra
ACS APPLIED ENERGY MATERIALS
(2019)