Article
Engineering, Electrical & Electronic
Michael Kismann, Thomas Riedl, Joerg K. N. Lindner
Summary: This article investigates the tailoring of Si nanostructure geometries on large areas using nanosphere lithography combined with metal-assisted wet-chemical etching. It demonstrates the formation of Si nanopencils and nanopillars with single and multiple constrictions by varying the HF/H2O2 ratio of the etching solution. Controlled oxidation in water vapor results in nanoscale Si inclusions surrounded by an amorphous SiO2 shell, which could have implications for advanced thermoelectric devices.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2021)
Article
Engineering, Electrical & Electronic
Nguyen Van Minh, Dang Van Hieu, Pham Van Tuan, Nguyen Duc Dung, Chu Manh Hoang
Summary: Silicon nano-pillars array can be fabricated on silicon wafer using nano-sphere lithography and metal assisted chemical etching. The height and diameter of the SiNPs are controlled by etching time and NSL respectively. The structural morphology and optical characteristics of the fabricated SiNPs are comprehensively investigated.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2022)
Article
Chemistry, Multidisciplinary
Ling-Yi Liang, Yu-Han Kung, Vincent K. S. Hsiao, Chih-Chien Chu
Summary: In this study, porous silicon (PSi) fabricated using metal-assisted chemical etching (MACE) was investigated as a substrate for the deposition of Au nanoparticles (NPs) for the reduction of nitroaromatic compounds. The high surface area of PSi allowed for efficient deposition of Au NPs, and the MACE method provided a well-defined porous structure in a single step. The catalytic activity of Au NPs on PSi was evaluated using the reduction of p-nitroaniline as a model reaction, and the results indicated that the catalytic activity was influenced by the etching time. Overall, the study highlighted the potential of PSi fabricated using MACE as a substrate for the deposition of metal NPs for catalytic applications.
Article
Chemistry, Multidisciplinary
Julian A. Michaels, Lukas Janavicius, Xihang Wu, Clarence Chan, Hsieh-Chih Huang, Shunya Namiki, Munho Kim, Dane Sievers, Xiuling Li
Summary: This paper presents a plasma-free, open-circuit, photo-induced metal-assisted chemical etch method for fabricating micro and nanoscale features on Silicon carbide without causing high energy ion-related surface damage. The comprehensive exploration of parameter space demonstrates the controllability and versatility of this technique in producing ordered arrays of micro and nanoscale SiC structures with porous or solid sidewalls, while elucidating the etching mechanism.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Engineering, Electrical & Electronic
Kirill A. Gonchar, Daniil Moiseev, Ivan Bozhev, Liubov A. Osminkina
Summary: Porous silicon nanowires (PSi NWs) were fabricated using a two step metal-assisted chemical etching method, and it was found that their structural and optical properties depend on the concentration of hydrogen peroxide. The thickness ratio of layers and size of nanocrystals can be tuned by choosing the required concentration of H2O2.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2021)
Review
Chemistry, Multidisciplinary
Antonio Alessio Leonardi, Maria Jose Lo Faro, Alessia Irrera
Summary: This article discusses the emerging technology of metal-assisted chemical etching (MACE) for the fabrication of silicon nanowires, comparing all the main routes for Si NWs and analyzing factors such as equipment cost, process complexity, repeatability, and the potential for commercial transfer in the field of microelectronics.
Article
Chemistry, Physical
Caroline Lima Salles, William Nemeth, Harvey L. Guthrey, Chun-Sheng Jiang, Matthew R. Page, Sumit Agarwal, Paul Stradins
Summary: This study demonstrates a new method for the fabrication of solar cells, which involves the creation of conducting pinholes using metal-assisted chemical etching at room temperature. The fabricated solar cells with passivating contacts show superior performance, expanding the possibilities for the design of solar cell materials.
ADVANCED ENERGY MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Shahnawaz Uddin, Md. Roslan Hashim, Mohd Zamir Pakhuruddin
Summary: The study examined the impact of annealing temperature on the surface morphology and optical properties of b-Si fabricated using AACE process, finding that annealing at 400 degrees Celsius resulted in the formation of optimal surface features.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Haibin Li, Shinya Kato, Tetsuo Soga
Summary: Through comparing different concentration silicon, it was found that high-doped silicon has the highest etching rate, contrary to existing reports. In addition, severe lateral etching of high-doped silicon was observed. Therefore, it is necessary to re-understand the etching characteristics and mechanism of high-doped silicon.
MATERIALS RESEARCH EXPRESS
(2022)
Article
Materials Science, Multidisciplinary
Yun Chen, Zijian Li, Dachuang Shi, Shankun Dong, Xin Chen, Jian Gao
Summary: A novel double-sided metal-assisted photochemical etching (double-sided MAPCE) technique was proposed to efficiently fabricate SiC nano-via arrays. The experimental results showed that the vertical etching rate of double-sided MAPCE was about 2.2 times higher than that of traditional MAPCE. The etching rate of SiC was closely related to the type of noble metal, the concentration of oxidant (H2O2), and the UV light power density. The proposed method is possible to be used to process wide bandgap semiconductors.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Engineering, Electrical & Electronic
Xue-Qing Liu, Rong Cheng, Jia-Xin Zheng, Shuang-Ning Yang, Bao-Xu Wang, BenFeng Bai, Qi-Dai Chen, Hong-Bo Sun
Summary: Blazed gratings can concentrate light energy to desired diffraction orders in optical detection devices. By utilizing femtosecond laser lithography and reactive ion etching on sapphire substrates, blazed gratings with high mechanical stability were fabricated, providing insights for the construction of micro-optical devices with potential applications under harsh conditions.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Michael J. Haslinger, Oliver S. Maier, Markus Pribyl, Philipp Taus, Sonja Kopp, Heinz D. Wanzenboeck, Kurt Hingerl, Michael M. Muehlberger, Elena Guillen
Summary: Structural anti-reflective coating and bactericidal surfaces, as well as many other effects, rely on high-aspect-ratio (HAR) micro- and nanostructures, and thus, are of great interest for a wide range of applications. In this research, we developed a UV-based nanoimprint lithography process to master and replicate high-aspect-ratio nanopillars, achieving the smallest possible diameters for dense and isolated arrangements. The stability of the imprinted nanopillars was significantly improved by coating them with a 20 nm gold layer and an additional 20 nm thick layer of SiN. The UV-NIL replication of high-aspect-ratio nanopillars with tip diameters down to 35 nm was demonstrated for the first time, making them suitable for various applications.
Article
Engineering, Electrical & Electronic
Nguyen Van Minh, Dang Van Hieu, Nghiem Thi Ha Lien, Chu Manh Hoang
Summary: This study investigates the factors affecting the fabrication technology of silicon nanopillars. The process includes assembling close-packed silica nanoparticle monolayers using the drop-coating method, forming non-close packed silica nanoparticle monolayers using HF vapor etching, and creating SiNPs using metal-assisted chemical etching (MACE). The observed experimental results are explained through proposed etching mechanisms.
JOURNAL OF MICRO-NANOPATTERNING MATERIALS AND METROLOGY-JM3
(2022)
Article
Materials Science, Multidisciplinary
Shahnawaz Uddin, Md Roslan Hashim, Mohd Zamir Pakhuruddin
Summary: This study investigated the fabrication of b-Si absorber using the AACE process for the first time, and found that b-Si fabricated with a 12 nm thick aluminum film exhibited the lowest Ravg and highest broadband light absorption. The findings demonstrate the potential of the AACE process for producing b-Si with superior broadband light absorption, which is important for photovoltaic applications.
MATERIALS CHEMISTRY AND PHYSICS
(2021)
Article
Chemistry, Analytical
Lansheng Zhang, Xiaoyang Chu, Feng Tian, Yang Xu, Huan Hu
Summary: This paper presents a cost-effective and scalable method for producing hierarchical micro-/nanostructured silicon surfaces. By using metal-assisted chemical etching, the researchers achieved superhydrophobic properties and a long ice delay time on the hierarchical micro-/nanostructured surfaces.
Article
Chemistry, Multidisciplinary
Shengshun Duan, Qiongfeng Shi, Jianlong Hong, Di Zhu, Yucheng Lin, Yinghui Li, Wei Lei, Chengkuo Lee, Jun Wu
Summary: This article introduces an electronic skin (e-skin) that mimics the physical-chemical and sensory properties of human skin, showing promise for use in robotic skins and skin-attachable wearables with multisensory functionalities. Most e-skins developed so far focus on simulating only the sensory functions of human skin, while this advanced e-skin, called Hygel e-skin, covers both sensory and physical-chemical properties. The Hygel e-skin demonstrates desirable characteristics such as stretchability, self-healing, biocompatibility, biodegradability, weak acidity, antibacterial activities, flame retardance, temperature adaptivity, function reconfigurability, and evolvability. It is applied as an on-robot e-skin and skin-attached wearable, exhibiting highly skin-like attributes in capturing multiple sensory information and enabling real-time gesture recognition through deep learning. This Hygel e-skin holds potential for applications in advanced robotics and as a skin-replaceable artificial skin.
Article
Chemistry, Multidisciplinary
Chengkuo Lee, Jingkai Zhou, Zixuan Zhang, Bowei Dong, Zhihao Ren, Weixin Liu
Summary: This article introduces an artificial intelligence-enhanced metamaterial waveguide sensing platform for the analysis of aqueous mixtures in the mid-infrared spectrum. With this platform, the absorption spectra of ternary mixtures in water can be successfully distinguished and decomposed to predict concentration. Additionally, accurate classification of 64 mixing ratios and four concentrations (below the detection limit of 972 ppm) with a classification accuracy of 98.88% and 92.86% respectively, as well as concentration prediction with root-mean-squared error ranging from 0.107% to 1.436%, are achieved. This research demonstrates the potential of further extending this sensing platform to a mid-infrared spectrometer-on-chip for data analytics of multiple organic components in aqueous environments.
Review
Chemistry, Analytical
Tianyiyi He, Feng Wen, Yanqin Yang, Xianhao Le, Weixin Liu, Chengkuo Lee
ANALYTICAL CHEMISTRY
(2023)
Review
Chemistry, Physical
Yanqin Yang, Xinge Guo, Minglu Zhu, Zhongda Sun, Zixuan Zhang, Tianyiyi He, Chengkuo Lee
Summary: This review presents the advancements of TENG-based electronics in areas such as materials, hybridization, systems integration, and applications in healthcare, environment monitoring, transportation, and smart homes. TENG technology, with its self-powered, cost-effective, and highly customizable advantages, is considered one of the most promising technologies for the development of Internet of Things/5G infrastructure.
ADVANCED ENERGY MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Siyu Xu, Zhihao Ren, Bowei Dong, Jingkai Zhou, Weixin Liu, Chengkuo Lee
Summary: Mid-infrared spectroscopy is a promising technique for molecule identification and label-free chemical sensing. Integrated photonic platforms built on lithium niobate substrates offer a solution to the electroabsorption issue in mid-infrared photonics. The proposed silicon-on-lithium-niobate platform demonstrates the potential for implementing integrated mid-infrared spectroscopic sensing systems.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Chemistry, Physical
Anxin Luo, Weihan Xu, Jiangyong Sun, Kunling Xi, Siyao Tang, Xinge Guo, Chengkuo Lee, Fei Wang
Summary: This paper proposes a vibration energy harvester with a double frequency-up conversion mechanism, which is capable of harvesting energy from ultra-low-frequency vibrations. The device can convert external vibrations from sub-Hertz to tens of Hertz and further to hundreds of Hertz, achieving a high conversion ratio of 8400. The comprehensive dynamic model proposed in this paper has been verified through theoretical analysis and COMSOL simulation, effectively analyzing the frequency conversion process and output voltage. When excited by a frequency of 0.2 Hz, the device can generate an average output power of 75 mu W with a compact size. Its non-contact design allows for application in sealed scenarios for smart city construction.
Review
Chemistry, Multidisciplinary
Hong Zhou, Liangge Xu, Zhihao Ren, Jiaqi Zhu, Chengkuo Lee
Summary: This review introduces the combination of machine learning (ML) and surface-enhanced spectroscopy techniques (SERS/SEIRA) and discusses the benefits of ML algorithms for SERS/SEIRA. It also highlights the applications of ML-combined SEIRA/SERS in molecular diagnostics and screening and provides perspectives on future developments in ML-integrated SEIRA/SERS.
NANOSCALE ADVANCES
(2023)
Article
Chemistry, Multidisciplinary
Manjuan Huang, Minglu Zhu, Xiaowei Feng, Zixuan Zhang, Tianyi Tang, Xinge Guo, Tao Chen, Huicong Liu, Lining Sun, Chengkuo Lee
Summary: The evolution of AIoT greatly promotes the development of smart cities by enabling comprehensive perception and seamless communication. However, the integration and sustainability of AIoT nodes are currently limited. In this study, an intelligent piezoelectric AIoT node called iCUPE is designed, which integrates energy harvesting and self powered sensing modules. It achieves continuous power supply over a wide frequency range and high-precision multifunctional vibration recognition. The proposed iCUPE is scalable and essential for AIoT implementation in diverse environments.
Article
Chemistry, Multidisciplinary
Qiongfeng Shi, Zhongda Sun, Xianhao Le, Jin Xie, Chengkuo Lee
Summary: A soft robotic perception system with remote object positioning and multimodal cognitive capability is developed by integrating an ultrasonic sensor with flexible triboelectric sensors. The system allows for accurate object positioning and identification, expanding the adaptability of current soft robotic systems in various applications.
Article
Chemistry, Multidisciplinary
Dongxiao Li, Hong Zhou, Ziwei Chen, Zhihao Ren, Cheng Xu, Xianming He, Tao Liu, Xin Chen, He Huang, Chengkuo Lee, Xiaojing Mu
Summary: Tailoring light-matter interactions via plasmonic nanoantennas (PNAs) is a breakthrough technology for spectroscopic applications. This study demonstrates that low interaction efficiency caused by detuning can be addressed by using overcoupled PNAs (OC-PNAs) with a high ratio of radiative to intrinsic loss rates, enabling ultrasensitive spectroscopy at strong plasmonic-molecular detuning. OC-PNAs achieve ultrasensitive molecule signals within a wavelength detuning range 248 cm(-1).
ADVANCED MATERIALS
(2023)
Article
Multidisciplinary Sciences
Jianxiong Zhu, Shanling Ji, Zhihao Ren, Wenyu Wu, Zhihao Zhang, Zhonghua Ni, Lei Liu, Zhisheng Zhang, Aiguo Song, Chengkuo Lee
Summary: We propose a synergistic methodology of artificial intelligence-enhanced ion mobility and mid-infrared spectroscopy, which achieves high accuracy in isopropyl alcohol identification and gas concentration prediction by leveraging the complementary features from sensing signals in different dimensions.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Yafeng Pang, Xingyi Zhu, Shuainian Liu, Chengkuo Lee
Summary: A gradient and multimodal triboelectric nanogenerator (GM-TENG) is proposed based on the nature triply periodic minimal surface (TPMS), showing high sensitivity and excellent multimodal monitoring for improving driving safety.
Review
Nanoscience & Nanotechnology
Kaustav Roy, Joshua En-Yuan Lee, Chengkuo Lee
Summary: This review discusses the research progress of thin-film PMUTs in the field of microultrasound, highlighting that the research in this field began 44 years ago with the development of functional piezoelectric thin-film materials. Three major companies are currently commercializing thin-film PMUTs on a bulk scale. The review comprehensively covers the extensive development of these devices' design, manufacturing, and function, including the global PMUT outlook, design principles, manufacturing methods, nonconventional PMUT designs, and category-wise applications.
MICROSYSTEMS & NANOENGINEERING
(2023)
Article
Biochemical Research Methods
Philippe Vachon, Srinivas Merugu, Jaibir Sharma, Amit Lal, Eldwin J. Ng, Yul Koh, Joshua E. -Y. Lee, Chengkuo Lee
Summary: This study presents microfabricated piezoelectric thin film membranes made via silicon diffusion for guided flexural wave generation as promising acoustofluidic actuators with low frequency, voltage, and power requirements. The guided wave propagation can be dynamically controlled to tune and confine the induced acoustofluidic radiation force and streaming. The membrane acoustic waveguide actuators offer a promising pathway for acoustofluidic applications such as biosensing, organoid production, and in situ analyte transport.
Article
Materials Science, Multidisciplinary
Yanqin Yang, Qiongfeng Shi, Zixuan Zhang, Xuechuan Shan, Budiman Salam, Chengkuo Lee
Summary: This research develops a digital-twin smart home system that utilizes robust TENG technology for smart home monitoring and multi-modality information generation. By eliminating the influence of environmental changes and achieving arbitrary position sensing, the accuracy of user identification is improved. Additionally, by projecting the information into virtual reality, the visualization of the smart home is achieved.
