Doyoung Kim, Seung Won Seon, Minkyung Shin, Jihwan Kim, Bogeun Kim, Janghoon Joo, Sang Uk Park, Wooseok Kim, Hee Kyu Lee, Byeong Woon Lee, Se Gi Lee, Su Eon Lee, Ji-Hun Seo, Seung Ho Han, Bong Hoon Kim, Sang Min Won
{"title":"Squid-inspired and wirelessly controllable display for active camouflage in aquatic-environment","authors":"Doyoung Kim, Seung Won Seon, Minkyung Shin, Jihwan Kim, Bogeun Kim, Janghoon Joo, Sang Uk Park, Wooseok Kim, Hee Kyu Lee, Byeong Woon Lee, Se Gi Lee, Su Eon Lee, Ji-Hun Seo, Seung Ho Han, Bong Hoon Kim, Sang Min Won","doi":"10.1038/s41528-024-00292-5","DOIUrl":"10.1038/s41528-024-00292-5","url":null,"abstract":"Achieving optimal camouflage in an aquatic environment necessitates the ability to modulate transmittance in response to the surrounding obscurity and potential threats. This adaptation involves a dynamic transition from transparency to a deep-blue color, especially in low-light or dark situations. Such a strategy promotes a seamless assimilation with the surroundings, enabling the absorption of searchlights and, subsequently, diminishing the risk of detection by predators. Therefore, the presence of sophisticated mechanisms that facilitates stable and efficient control of transmittance is imperative, enabling smooth transition between transparent and deep-blue hues within the aquatic environment. This study presents nature-inspired programmable camouflage system that integrates an electrochromic display as the primary transmittance change element and a wireless base module for power and data transmission. Such technology offers a robust and flexible construction, ensuring stable operation as demonstrated through mechanical-fatigue experiments and quantitative simulation. A custom circuit and a power-control software package enable active control of multiple electrochromic displays while submerged in water.","PeriodicalId":48528,"journal":{"name":"npj Flexible Electronics","volume":" ","pages":"1-10"},"PeriodicalIF":14.6,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41528-024-00292-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140030060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Multilayer stretchable electronics with designs enabling a compact lateral form","authors":"Dongwuk Jung, Hunpyo Ju, Sungbum Cho, Taeyeon Lee, Changeui Hong, Jongho Lee","doi":"10.1038/s41528-024-00299-y","DOIUrl":"10.1038/s41528-024-00299-y","url":null,"abstract":"Stretchable electronics are of huge interest as they can be useful in various irregular non-planar or deformable surfaces including human bodies. High density multi-functional stretchable electronics are beneficial as they can be reliably used in more compact regions. However, simply stacking multiple layers may increase induced strain, reducing degree of stretchability. Here, we present the design approach for the stretchable multilayer electronics that provide a similar degree of stretchability compare to a single layer electronics although the multilayer electronics are in much more compact form. We provide experimental and computational analyses for the benefits of the approach along with demonstrations with compact form of the multi-functional stretchable implantable bio-electronics and of the stretchable multilayer passive matrix LEDs array. The results presented here should be useful for a wide range of applications that require stretchable high-density electronics.","PeriodicalId":48528,"journal":{"name":"npj Flexible Electronics","volume":" ","pages":"1-9"},"PeriodicalIF":14.6,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41528-024-00299-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139916801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yifan Deng, Fan Bu, Yujie Wang, Pei Song Chee, Xiangye Liu, Cao Guan
{"title":"Stretchable liquid metal based biomedical devices","authors":"Yifan Deng, Fan Bu, Yujie Wang, Pei Song Chee, Xiangye Liu, Cao Guan","doi":"10.1038/s41528-024-00298-z","DOIUrl":"10.1038/s41528-024-00298-z","url":null,"abstract":"Pursuit of improved living quality has stimulated great demand for high-performance conformal healthcare devices in modern human society. However, manufacturing of efficient, comfortable and stretchable biomedical apparatus faces huge challenges using traditional materials. Liquid metals (LMs) show remarkable potential to solve this problem due to their extraordinary biocompatibility, stretchability, thermal and electrical conductivity. In recent years, tremendous explorations have attempted to make stretchable biomedical devices with LMs. Herein, we review the stretchable LM-based biomedical devices on the topics of disease treatment and human function augmenting. The representative and up-to-date neural interfaces, alloy cement, e-vessels, soft heaters, exoskeletons, and e-skins are summarized. The existing issues of LMs applied for biomedical devices are also discussed. This review can provide guidance for the follow-up research in LM-based biomedical devices.","PeriodicalId":48528,"journal":{"name":"npj Flexible Electronics","volume":" ","pages":"1-22"},"PeriodicalIF":14.6,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41528-024-00298-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139908945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jinwoo Lee, Kangkyu Kwon, Ira Soltis, Jared Matthews, Yoon Jae Lee, Hojoong Kim, Lissette Romero, Nathan Zavanelli, Youngjin Kwon, Shinjae Kwon, Jimin Lee, Yewon Na, Sung Hoon Lee, Ki Jun Yu, Minoru Shinohara, Frank L. Hammond, Woon-Hong Yeo
{"title":"Intelligent upper-limb exoskeleton integrated with soft bioelectronics and deep learning for intention-driven augmentation","authors":"Jinwoo Lee, Kangkyu Kwon, Ira Soltis, Jared Matthews, Yoon Jae Lee, Hojoong Kim, Lissette Romero, Nathan Zavanelli, Youngjin Kwon, Shinjae Kwon, Jimin Lee, Yewon Na, Sung Hoon Lee, Ki Jun Yu, Minoru Shinohara, Frank L. Hammond, Woon-Hong Yeo","doi":"10.1038/s41528-024-00297-0","DOIUrl":"10.1038/s41528-024-00297-0","url":null,"abstract":"The age and stroke-associated decline in musculoskeletal strength degrades the ability to perform daily human tasks using the upper extremities. Here, we introduce an intelligent upper-limb exoskeleton system that utilizes deep learning to predict human intention for strength augmentation. The embedded soft wearable sensors provide sensory feedback by collecting real-time muscle activities, which are simultaneously computed to determine the user’s intended movement. Cloud-based deep learning predicts four upper-limb joint motions with an average accuracy of 96.2% at a 500–550 ms response rate, suggesting that the exoskeleton operates just by human intention. In addition, an array of soft pneumatics assists the intended movements by providing 897 newtons of force while generating a displacement of 87 mm at maximum. The intent-driven exoskeleton can reduce human muscle activities by 3.7 times on average compared to the unassisted exoskeleton.","PeriodicalId":48528,"journal":{"name":"npj Flexible Electronics","volume":" ","pages":"1-13"},"PeriodicalIF":14.6,"publicationDate":"2024-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41528-024-00297-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139715272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yunxia Jin, Mengxia Yu, Dat T. Nguyen, Xin Yang, Zhipeng Li, Ze Xiong, Chenhui Li, Yuxin Liu, Yong Lin Kong, John S. Ho
{"title":"Digitally-defined ultrathin transparent wireless sensor network for room-scale imperceptible ambient intelligence","authors":"Yunxia Jin, Mengxia Yu, Dat T. Nguyen, Xin Yang, Zhipeng Li, Ze Xiong, Chenhui Li, Yuxin Liu, Yong Lin Kong, John S. Ho","doi":"10.1038/s41528-024-00293-4","DOIUrl":"10.1038/s41528-024-00293-4","url":null,"abstract":"Wireless and battery-free radio-frequency (RF) sensors can be used to create physical spaces that ambiently sense and respond to human activities. Making such sensors ultra-flexible and transparent is important to preserve the aesthetics of living environments, accommodate daily activities, and functionally integrate with objects. However, existing RF sensors are unable to simultaneously achieve high transparency, flexibility, and the electrical conductivity required for remote room-scale operation. Here, we report 4.5 µm RF tag sensors achieving transparency exceeding 90% that provide capabilities in room-scale ambient wireless sensing. We develop a laser-assisted water-based adhesion-reversion process to digitally realize computer-aided RF design at scale. By individually tagging multiple objects and regions of the human body, we demonstrate multiplexed wireless tracking of human-environment interactions and physiological signals at a range of up to 8 m. These radio-frequency identification sensors open opportunities for non-intrusive wireless sensing of daily living spaces for applications in health monitoring and elderly care.","PeriodicalId":48528,"journal":{"name":"npj Flexible Electronics","volume":" ","pages":"1-10"},"PeriodicalIF":14.6,"publicationDate":"2024-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41528-024-00293-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139700695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhibin Li, Jing Yang, Yuxuan Zhang, Peiyan Geng, Jiansong Feng, Bin Chen, Xu Zhang, Guojiang Yuan, Xiaolong Chen, Taihong Wang
{"title":"Ultrafast readout, crosstalk suppression iontronic array enabled by frequency-coding architecture","authors":"Zhibin Li, Jing Yang, Yuxuan Zhang, Peiyan Geng, Jiansong Feng, Bin Chen, Xu Zhang, Guojiang Yuan, Xiaolong Chen, Taihong Wang","doi":"10.1038/s41528-024-00295-2","DOIUrl":"10.1038/s41528-024-00295-2","url":null,"abstract":"The development of iontronic skin (I-skin) capable of ultrafast sensing in a wide pressure range, comparable to human skin, is of paramount importance for intelligent robotics. However, this remains a major challenge due to the lack of iontronic array architectures that can achieve ultrafast readout and crosstalk-free under large capacitance response generated within a wide pressure range. Here, we report a frequency-coding architecture of artificial ion mechanoreceptor skin (AIM-skin) that can provide a universal mode of iontronic array sensing and bypass the dependence of complex integrated back-end interface electronics. Notably, the successful implementation of orthogonal frequency coding in the AIM-skin with high sensitivity and ultrawide pressure range achieve ultrafast parallel readout for the spatiotemporal mechanical stimuli. Furthermore, the parallel zero-potential mechanism (PZPM) of the architecture effectively mitigates electrical crosstalk between sensing units. We have demonstrated that combhination of proposed device and deep learning has a broad application prospect in intelligent human-machine interaction and real-time dynamic robotic manipulation.","PeriodicalId":48528,"journal":{"name":"npj Flexible Electronics","volume":" ","pages":"1-12"},"PeriodicalIF":14.6,"publicationDate":"2024-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41528-024-00295-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139661020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Phase transition and electrical conversion properties of Ge/Sb nano-multilayer films on flexible substrates","authors":"Cheng Wang, Yifeng Hu, Li Li","doi":"10.1038/s41528-024-00296-1","DOIUrl":"10.1038/s41528-024-00296-1","url":null,"abstract":"Flexible information memory is the key component of flexible electronic devices and the core of intelligent wearable devices. In this paper, Ge/Sb multilayer phase change films of various thickness ratios were prepared using polyether ether ketone as substrate, and their flexible phase change properties and device conversion characteristics were studied. After bending for 100000 times and bending experiments with different bending radius, the film can still realize the transition from amorphous to crystalline states, and the resistance fluctuation was small. Bending, stretching and pressing of the film resulted in grain refinement and increasing of crystalline resistance. The flexible electronic devices using Ge/Sb multilayer films were prepared. The phase change memory device can realize reversible conversion between SET and RESET states with different pulse widths in flat, bent states and after bending many times. All findings show that Ge/Sb multilayer films on PEEK substrate have broad application prospects in high-performance flexible memory in the future.","PeriodicalId":48528,"journal":{"name":"npj Flexible Electronics","volume":" ","pages":"1-9"},"PeriodicalIF":14.6,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41528-024-00296-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139655706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yoonseok Park, Haiwen Luan, Kyeongha Kwon, Ted S. Chung, Seyong Oh, Jae-Young Yoo, Gooyoon Chung, Junha Kim, Suhyeon Kim, Sung Soo Kwak, Junhwan Choi, Hoang-Phuong Phan, Seonggwang Yoo, Hyoyoung Jeong, Jaeho Shin, Sang Min Won, Hong-Joon Yoon, Yei Hwan Jung, John A. Rogers
{"title":"Soft, full Wheatstone bridge 3D pressure sensors for cardiovascular monitoring","authors":"Yoonseok Park, Haiwen Luan, Kyeongha Kwon, Ted S. Chung, Seyong Oh, Jae-Young Yoo, Gooyoon Chung, Junha Kim, Suhyeon Kim, Sung Soo Kwak, Junhwan Choi, Hoang-Phuong Phan, Seonggwang Yoo, Hyoyoung Jeong, Jaeho Shin, Sang Min Won, Hong-Joon Yoon, Yei Hwan Jung, John A. Rogers","doi":"10.1038/s41528-024-00294-3","DOIUrl":"10.1038/s41528-024-00294-3","url":null,"abstract":"Variations in parameters associated with the ambient environment can introduce noise in soft, body-worn sensors. For example, many piezoresistive pressure sensors exhibit a high degree of sensitivity to fluctuations in temperature, thereby requiring active compensation strategies. The research presented here addresses this challenge with a multilayered 3D microsystem design that integrates four piezoresistive sensors in a full-Wheatstone bridge configuration. An optimized layout of the sensors relative to the neutral mechanical plane leads to both an insensitivity to temperature and an increased sensitivity to pressure, relative to previously reported devices that rely on similar operating principles. Integrating this 3D pressure sensor into a soft, flexible electronics platform yields a system capable of real-time, wireless measurements from the surface of the skin. Placement above the radial and carotid arteries yields high-quality waveforms associated with pulsatile blood flow, with quantitative correlations to blood pressure. The results establish the materials and engineering aspects of a technology with broad potential in remote health monitoring.","PeriodicalId":48528,"journal":{"name":"npj Flexible Electronics","volume":" ","pages":"1-8"},"PeriodicalIF":14.6,"publicationDate":"2024-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41528-024-00294-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139577499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Paul Čvančara, Giacomo Valle, Matthias Müller, Inga Bartels, Thomas Guiho, Arthur Hiairrassary, Francesco Petrini, Stanisa Raspopovic, Ivo Strauss, Giuseppe Granata, Eduardo Fernandez, Paolo M. Rossini, Massimo Barbaro, Ken Yoshida, Winnie Jensen, Jean-Louis Divoux, David Guiraud, Silvestro Micera, Thomas Stieglitz
{"title":"Author Correction: Bringing sensation to prosthetic hands—chronic assessment of implanted thin-film electrodes in humans","authors":"Paul Čvančara, Giacomo Valle, Matthias Müller, Inga Bartels, Thomas Guiho, Arthur Hiairrassary, Francesco Petrini, Stanisa Raspopovic, Ivo Strauss, Giuseppe Granata, Eduardo Fernandez, Paolo M. Rossini, Massimo Barbaro, Ken Yoshida, Winnie Jensen, Jean-Louis Divoux, David Guiraud, Silvestro Micera, Thomas Stieglitz","doi":"10.1038/s41528-023-00288-7","DOIUrl":"10.1038/s41528-023-00288-7","url":null,"abstract":"","PeriodicalId":48528,"journal":{"name":"npj Flexible Electronics","volume":" ","pages":"1-1"},"PeriodicalIF":14.6,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41528-023-00288-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139379332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Rotating square tessellations enabled stretchable and adaptive curved display","authors":"Yang Deng, Kuaile Xu, Rui Jiao, Weixuan Liu, Yik Kin Cheung, Yongkai Li, Xiaoyi Wang, Yue Hou, Wei Hong, Hongyu Yu","doi":"10.1038/s41528-023-00291-y","DOIUrl":"10.1038/s41528-023-00291-y","url":null,"abstract":"Curved displays can adjust their shape to accommodate different objects and are used in electronics and decorative lighting. Due to the immutable pixel spacing, existing commercial curved displays are flexible but not compatible with undevelopable surfaces. Inspired by kirigami and auxetic structures, we propose an approach that combines luminescent elements and rotating square tessellations to create a stretchable, arbitrary curve adaptive display. We connect square islands by vertical interconnects to relieve the stress concentration and provide extra deformation patterns. The vertical interconnects are patterned on a flexible printed circuit board (FPCB) using laser cutting and folded up via specially designed molds. Further, the freed-up space by folded interconnects allows the structure to be compressed. A prototype stretchable display is demonstrated that it can maintain electrical performance under biaxial strain and adapt to different Gaussian curvature surfaces, including cylindrical, spherical, saddle and arbitrary surfaces. Theoretical models and finite element calculations are established to describe the tensile behavior of the structures under different boundary conditions and agree with the experimental results. This proposed technology paves a feasible solution of mass production of adaptive curved displays and sets the trend for the next-generation display.","PeriodicalId":48528,"journal":{"name":"npj Flexible Electronics","volume":" ","pages":"1-10"},"PeriodicalIF":14.6,"publicationDate":"2024-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41528-023-00291-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139110173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}