Southeast University, Nanjing 211189, China
X. Z. Lang*, X. D. Wang, J. Ma, and T. Qiu, “Flexible fabrication of new-type porous anodic alumina membranes with tunable geometric features by low-cost nanoimprint lithography”, Nanoscale Advances, doi: 10.1039/D0NA00916D (2021).
A novel process for the flexible fabrication of new-type porous anodic alumina (PAA) membranes with tunable geometric features is described. In this process, the conventional PAA template as a cost-effective nanoimprint stamp is employed to transfer the anti-structure nanopits onto aluminum sheet substrates, and the subsequent guided anodization of the pre-patterned substrates leads to new-type PAAs. By further adjusting the anode voltages of PAA stamps, imprinting pressures and guided anode voltages, a series of new-type PAAs with controlled para-pore spacing, surface topography and nanopore arrangement are achieved. The new-type PAAs provide a low-cost flexible option for the preparation of arrays with utility in photonic, electronic and magnetic devices.
R. Wang, C. X. Xu*, D. T. You, X. X. Wang, J. P. Chen, Z. L. Shi, Q. N. Cui, and T. Qiu*, “Plasmon–exciton coupling dynamics and plasmonic lasing in a core–shell nanocavity”, Nanoscale, vol. 13, iss. 14, pp. 6780-6785 (2021). [Front Cover]
Plasmonic nanolasers based on the spatial localization of surface plasmons (SPs) have attracted considerable interest in nanophotonics, particularly in the desired application of optoelectronic and photonic integration, even breaking the diffraction limit. Effectively confining the mode field is still a basic, critical and challenging approach to improve optical gain and reduce loss for achieving high performance of a nanolaser. Here, we designed and fabricated a semiconductor/metal (ZnO/Al) core–shell nanocavity without an insulator spacer by simple magnetron sputtering. Both theoretical and experimental investigations presented plasmonic lasing behavior and SP-exciton coupling dynamics. The simulation demonstrated the three-dimensional optical confinement of the light field in the core–shell nanocavity, while the experiments revealed a lower threshold of the optimized ZnO/Al core–shell nanolaser than the same-sized ZnO photonic nanolaser. More importantly, the blue shift of the lasing mode demonstrated the SP-exciton coupling in the ZnO/Al core–shell nanolaser, which was also confirmed by low-temperature photoluminescence (PL) spectra. The analysis of the Purcell factor and PL decay time revealed that SP-exciton coupling accelerated the exciton recombination rate and enhanced the conversion of spontaneous radiation into stimulated radiation. The results indicate an approach to design a real nanolaser for promising applications.
L. L. Lan, Y. M. Gao, X. C. Fan, M. Z. Li, Q. Hao, and T. Qiu*, “The origin of ultrasensitive SERS sensing beyond plasmonics”, Frontiers of Physics, vol. 16, iss. 4, Article Number: 43300 (2021). [Invited Review]
Plasmon-free surface-enhanced Raman scattering (SERS) substrates have attracted tremendous attention for their abundant sources, excellent chemical stability, superior biocompatibility, good signal uniformity, and unique selectivity to target molecules. Recently, researchers have made great progress in fabricating novel plasmon-free SERS substrates and exploring new enhancement strategies to improve their sensitivity. This review summarizes the recent developments of plasmon-free SERS substrates and specially focuses on the enhancement mechanisms and strategies. Furthermore, the promising applications of plasmon-free SERS substrates in biomedical diagnosis, metal ions and organic pollutants sensing, chemical and biochemical reactions monitoring, and photoelectric characterization are introduced. Finally, current challenges and future research opportunities in plasmon-free SERS substrates are briefly discussed.
单分子检测代表分子检测灵敏度的极限，能够提供传统检测方式无法提供的物理信息，在化学分析、 分子动力学机理、蛋白质解析等领域具有广阔的应用前景，具有重要的科学研究价值。具体而言，单分子 检测能对复杂体系中的分子进行识别和计数，给出分子的分布信息；也可以对单个分子在吸附、反应等过 程中的实时衍变进行追踪，研究分子动力学的内在机制。单分子表面增强拉曼散射是单分子检测领域最近 兴起的一门新方法，其特色在于具有特异性分子识别能力，可以提供分子成键变化等动态信息。这种方法 适用于研究分子的演化过程、分子与环境的电荷相互作用，从而揭示分子的反应途径、分布状态、吸附方 式、电荷交换等重要信息。单分子表面增强拉曼散射的概念提出较早，但是缺乏高效的采集方法和精确的 判定依据，本文将对采集方法的优化进行梳理分析，从非统计学和统计学两个角度对其进行讨论，并重点 对双分子分析检测法做详细介绍。另一方面，由于单分子表面增强拉曼散射研究涉及各种交叉学科、内涵 广泛，相关研究需要对光谱背后的相关机制有着深刻的理解和认识。为此，本文基于当前的相关研究工作， 从分子漂移、光谱闪烁以及展宽等特有现象入手，分析了单分子表面增强拉曼散射的波动特征及其对应的 物理机制，并对其应用前景做了简要探讨。
Y. M. Yang*, F. Kong, J. Y. Fan, X. C. Fan, M. Z. Li, and T. Qiu*, “Stability of the structure and redox state of ferricytochrome c in the desolvation process”, Vibrational Spectroscopy, vol. 113, Article Number: 103220 (2021).
Stability of the structure and redox state of ferricytochrome c during continuous changing of the hydration environment from dilute solution to condensed phase was studied based on real-time resonance Raman measurement. Our experimental results indicated that the structure and redox state of ferricytochrome c were sufficiently maintained during the entire desolvation process, which reflected that the stabilizing excluded-volume effect was stronger than the destabilizing crowder-protein interaction, at the case of globular mini-protein itself acting as the crowder. Rapid reduction of ferricytochrome c was observed at measurement sites at the time of solution to condensed phase transition. Similar phenomenon was observed on cytochrome c adsorbed on indium tin oxide surface. At present conditions, the rapid reduction was found to be derived mainly from thermal reduction under laser illumination and secondarily from photoreduction induced by the residual adsorbed ferrocyanide anions. After re-dissolved, the protein which had undergone sufficient desolvation recovered the structure and redox state in the initial solution phase, suggesting that the crowding effect in solution prevented large protein deformations observed in gas phase condition.
M. Z. Li, Y. M. Gao, X. C. Fan, Y. J. Wei, Q. Hao, and T. Qiu*, “Origin of layer-dependent SERS tunability in 2D transition metal dichalcogenides”, Nanoscale Horizons, vol. 6, iss. 2, pp. 186-191 (2021).
Two-dimensional (2D) semiconductors are expected to replace noble metals to become the matrix materials of the next generation of commercial surface-enhanced Raman scattering (SERS) chips. Herein, we systematically studied the influence of the interlayer interaction on the SERS activity of 2D semiconductors from a brand-new perspective and comprehensively analyzed the physicochemical process of 2D semiconductor interlayer modulated SERS. Taking transition metal dichalcogenides as examples, we chose PtSe2 with strong interlayer interactions and ReS2 with weak interlayer interactions to analyze the physicochemical process of 2D semiconductor interlayer modulated SERS by first-principles calculations. PtSe2 and ReS2 samples with various thicknesses were prepared respectively, and the results of comparative experiments proved that the layer-dependent SERS tunability of 2D semiconductors is directly related to the interlayer interaction. This work provided a novel method for further improving the SERS detection limit of 2D semiconductors and a possible strategy for the industrial upgrading of commercial SERS chips.
Q. Hao, M. Z. Li, J. W. Wang, X. C. Fan, J. Jiang, X. X. Wang, M. S. Zhu, T. Qiu*, L. B. Ma, P. K. Chu, and O. G. Schmidt, “Flexible Surface-Enhanced Raman Scattering Chip: A Universal Platform for Real-Time Interfacial Molecular Analysis with Femtomolar Sensitivity”, ACS Applied Materials & Interfaces , vol. 14, iss. 48, pp. 54174-54180 (2020).
We propose and demonstrate a flexible surface-enhanced Raman scattering (SERS) chip as a versatile platform for femtomolar detection and real-time interfacial molecule analysis. The flexible SERS chip is composed of a flexible and transparent membrane and embedded plasmonic dimers with ultrahigh particle density and ultrasmall dimer gap. The chip enables rapid identification for residuals on solid substrates with irregular surfaces or dissolved analytes in aqueous solution. The sensitivity for liquid-state measurement is down to 0.06 molecule per dimers for 10–14 mol·L–1 Rhodamine 6G molecule without molecule enrichment. Strong signal fluctuation and blinking are observed at this concentration, indicating that the detection limit is close to the single-molecule level. Meanwhile, the homogeneous liquid environment facilities accurate SERS quantification of analytes with a wide dynamic range. The synergy of flexibility and liquid-state measurement opens up avenues for the real-time study of chemical reactions. The reduction from p-nitrothiophenol (PNTP) to p-aminothiophenol (PATP) in the absence of the chemical reducing agents is observed at liquid interfaces by in situ SERS measurements, and the plasmon-induced hot electron is demonstrated to drive the catalytic reaction. We believe this robust and feasible approach is promising in extending the SERS technique as a general method for identifying interfacial molecular traces, tracking the evolution of heterogeneous reactions, elucidating the reaction mechanisms, and evaluating the environmental effects such as pH value and salty ions in SERS.
With the intrinsic drawbacks of high processing costs, expensive raw materials and poor product-stability, the practical applications of commercial noble metal surface-enhanced Raman scattering (SERS) chips have been severely impeded. Thus, it comes as a significant challenge to develop an uncomplicated preparation method and search for low-cost candidates for highly-sensitive commercial SERS chips. Herein, we come up with a facile and universal approach to fabricate a series of plasmonic metal carbide SERS chips. This is the first time that tungsten carbide, molybdenum carbide, and niobium carbide are reported as SERS materials with cheap prices. Furthermore, we prove that the high SERS activity of these materials comes from strong localized surface plasmon resonance effects. These metal carbide chips could realize the detection of diverse organic molecules, and the detection limit concentration of rhodamine 6G was found to be below 10-8 M, which is even lower than some of the noble metal SERS substrates. Our work provides an efficient strategy to upgrade the industries of commercial SERS chips.
X. Y. Hou, Q. Lin, Y. J. Wei, Q. Hao, Z. H. Ni*, and T. Qiu*, “Surface-Enhanced Raman Scattering Monitoring of Oxidation States in Defect-Engineered Two-Dimensional Transition Metal Dichalcogenides”, The Journal of Physical Chemistry Letters , vol. 11, iss. 19, pp. 7981-7987 (2020).
Recent studies have found that some transition metal dichalcogenides (TMDs)with their own defects are difficult to store in the air for a long time. Worse stability of TMDsunder extreme conditions has also been reported. Therefore, monitoring the oxidation anddegradation processes of TMDs can directly guide the stability prediction of TMD-baseddevices and monitor TMDs quality. Herein, with the case of molybdenum disulfide, UV−ozone defect engineering is used to simulate the oxidation and degradation of TMDs undersevere conditions. Surface-enhanced Raman scattering based on a chemical mechanism wasfirst introduced to the dynamic monitoring of defect evolution in the oxidation anddegradation of TMDs, and succeeds in tracking the TMDs oxidation state by the quantitativemethod. It is expected that this technology can be extended to the quantification and trackingof oxidation and degradation of other 2D materials.
X. C. Fan, Q. Hao, M. Z. Li, X. Y. Zhang, X. Z. Yang, Y. F. Mei, and T. Qiu*, “Hotspots on the Move: Active Molecular Enrichment by Hierarchically Structured Micromotors for Ultrasensitive SERS Sensing”, ACS Applied Materials & Interfaces , vol. 12, pp. 28783–28791 (2020). [Highlighted by Chemical & Engineering News: "Chemistry in Pictures: The swimmers who do SERS"]
Surface-enhanced Raman scattering (SERS) is recognized as one of the most sensitive spectroscopic tools for chemical and biological detections. Hotspots engineering has expedited promotion of SERS performance over the past few decades. Recently, molecular enrichment has proven to be another effective approach to improve the SERS performance. In this work, we propose a concept of “motile hotspots” to realize ultrasensitive SERS sensing by combining hotspots engineering and active molecular enrichment. High-density plasmonic nanostructure-supporting hotspots are assembled on the tubular outer wall of micromotors via nanoimprint and rolling origami techniques. The dense hotspots carried on these hierarchically structured micromotors (HSMs) can be magnet-powered to actively enrich molecules in fluid. The active enrichment manner of HSMs is revealed to be effective in accelerating the process of molecular adsorption. Consequently, SERS intensity increases significantly because of more molecules being adjacent to the hotspots after active molecular enrichment. This “motile hotspots” concept provides a synergistical approach in constructing a SERS platform with high performance. Moreover, the newly developed construction method of HSMs manifests the possibility of tailoring tubular length and diameter as well as surface patterns on the outer wall of HSMs, demonstrating good flexibility in constructing customized micromotors for various applications.
H. Huang, X. S. Wang, D. Philo, F. Ichihara, H. Song, Y. X. Li, D. Li, T. Qiu*, S. Y. Wang*, and J. H. Ye*, “Toward visible-light-assisted photocatalytic nitrogen fixation: A titanium metal organic framework with functionalized ligands”, Applied Catalysis B: Environmental , vol. 267, Article Number: 118686 (2020).
The fixation of atmospheric dinitrogen to ammonia is one of the most essential processes for sustaining life. Since the N≡N bond in dinitrogen is one of the strongest bonds in chemistry, it remains a grand challenge to develop efficient catalysts for fixation of N2 under ambient conditions. Herein we report for the first time on visible-light-assisted photocatalytic nitrogen fixation by metal organic framework material at room temperature and pressure. The Ti3+ species induced by electron transfer from ligand-to-metal charge transfer process provide active sites for N2 reduction. Furthermore, visible-light-assisted photocatalytic N2 fixation is achieved by ligands functionalization which extend the light harvesting of the MOF to visible region. The integration of Ti sites and amine-functionalized linkers in NH2-MIL-125 (Ti) shows the highest visible light photocatalysis efficiency at a rate of 12.3 μmol g−1 h−1. This Ti MOF system therefore shows a potential as a new design of combining light-harvesting and catalytic components in a single solid platform for green NH3 production.
X. Y. Hou, X. Y. Zhang, Q. W. Ma, X. Tang, Q. Hao, Y. C. Cheng*, and T. Qiu*, “Alloy Engineering in Few‐Layer Manganese Phosphorus Trichalcogenides for Surface‐Enhanced Raman Scattering”, Advanced Functional Materials , vol. 30, iss. 12, Article Number: 1910171 (2020).
Manganese phosphorus trichalcogenides are widely used in the field of photocatalysis and magnetic studies due to their broadband gaps. Herein, an alloy engineering method for the few‐layer manganese phosphorus trichalcogenides (MnPS3–xSex, 0 ≤ x ≤ 3) in surface‐enhanced Raman scattering (SERS) is reported. A new strategy, with the coupling of exciton resonance (µex) and photoinduced charge transfer (PICT), is applied to screen out materials for SERS enhancement. According to the calculation of density functional theory, the bandgap of manganese phosphorus trichalcogenides (MnPS3) can be adjusted to match the band energy of Rhodamine 6G molecules by alloy engineering. Furthermore, a series of few‐layer MnPS3–xSex (0 ≤ x ≤ 3) are fabricated to study the PICT‐induced SERS behavior under resonance excitation. The good performance with a detection limit down to 10−9 m indicates that the synergistic resonances between µex and PICT are crucial to the enhancement.
X. C. Fan, Q. Hao*, T. Qiu, and Paul K. Chu*, “Improving the performance of light-emitting diodes via plasmonic-based strategies”, Journal of Applied Physics , vol. 127, iss. 4, Article Number: 040901 (2020). [Invited Review]
Light-emitting diodes (LEDs), featuring long lifetime, small size, and low energy consumption, are increasingly popular for displays and general light sources. In the past decades, new light-emitting materials and novel device configurations are being continuously investigated to obtain highly efficient LEDs. Nevertheless, the unsatisfying external quantum efficiency severely limits their commercial implementation. Among all the approaches to boost the efficiency of LEDs, the incorporation of plasmonic structures exhibits great potential in increasing the spontaneous emission rates of emitters and improving the light extraction efficiency. In this Perspective, the methods to deal with challenges in quantum-well-based LEDs and organic LEDs by employing plasmonic materials are described, the mechanisms of plasmonic-based strategies to improve the light generation and extraction efficiency are discussed, and the plasmonic control over directional emission of phosphors is introduced as well. Moreover, important issues pertaining to the design, fabrication, and manipulation of plasmonic structures in LEDs to optimize the device performance, as well as the selection roles in finding appropriate plasmonic materials and structures for desired LED devices, are explained. This perspective lists the challenges and opportunities of plasmonic LEDs, with the aim of providing some insights into the future trends of plasmonic LEDs.
L. L. Lan, X. Y. Hou, Y. M. Gao, X. C. Fan, and T. Qiu*, “Inkjet-printed paper-based semiconducting substrates for surface-enhanced Raman spectroscopy”, Nanotechnology , vol. 31, iss. 5, Article Number: 055502 (2020).
As a powerful analytical tool of molecular detection, surface-enhanced Raman spectroscopy (SERS) has attracted great attention in varied fields. However, it has seriously impeded the development of SERS that the preparation process is generally complicated and traditional substrates lack eco-friendliness, economy and flexibility. Herein, we fabricated the inkjet-printed paper-based semiconducting SERS substrates for the first time via an inexpensive office inkjet printer with representative two-dimensional MoO3−x nanosheets ink. Compared with conventional substrates, these paper-based semiconducting substrates not only could meet the requirements of simple and large-scale preparation, but also realize efficient sample collection by merely swabbing the surface. We obtained the detection limit concentration of rhodamine 6G as low as 10–7 M. Furthermore, these flexible paper-based substrates were successfully applied to detect crystal violet and malachite green on the fish surface by swabbing. With immense potentiality in practical applications, the inkjet-printed paper-based semiconducting SERS substrates are expected to open a new prospect for SERS.
Noble metal surface-enhanced Raman scattering (SERS) chips based on plasmonic nanostructures have been commercialized. However, replacing the complex and high-cost preparation method remains a challenge. In this case, the expansion of noble metal-comparable SERS materials for commercial chip applications is a fundamental issue. Non-metals fabricated using the chemical method have achieved SERS activity comparable to that of noble metals, but it is hard to obtain planar materials using this technique and therefore non-metal chips have not yet been developed. Herein, we systematically studied the possibility that transition metal oxides (TMOs) could rival noble metals for SERS activity. Nonstoichiometric group-IVB, VB and VIB TMOs materials were fabricated using a general strategy based on magnetron sputtering with a H2 annealing treatment. The limit of detection was below 10−9 M owing to the process of photoinduced charge transfer (PICT). For the first time, we obtained commercially viable non-metal SERS chips using a convenient and cheap physical method. A theoretical explanation of PICT proves that this technique can be used to achieve more SERS chips.
X. C. Fan, M. Z. Li, Q. Hao, M. S. Zhu, X. Y. Hou, H. Huang, L. B. Ma, O. G. Schmidt, and T. Qiu*, “High SERS Sensitivity Enabled by Synergistically Enhanced Photoinduced Charge Transfer in Amorphous Nonstoichiometric Semiconducting Films”, Advanced Materials Interfaces , vol. 6, iss. 19, Article Number: 1901133 (2019).
Semiconducting surface‐enhanced Raman scattering (SERS) materials have attracted tremendous attention for their good signal uniformity, chemical stability, and biocompatibility. Here, a new concept to design high sensitivity semiconducting SERS substrates through integration of both amorphous and nonstoichiometric features of WO3−x thin films is presented. The integration of these two features provides narrower bandgap, additional defect levels within the bandgap, stronger exciton resonance, and higher electronic density of states near the Fermi level. These characteristics lead to a synergy to promote the photoinduced charge transfer resonance between analytes and substrate by offering efficient routes of charge escaping and transferring as well as strong vibronic coupling, thus realizing high SERS activity on amorphous nonstoichiometric WO3−x films.
Surface-enhanced Raman spectroscopy (SERS), a sensitive analytical technique that has single molecular sensitivity, has attracted continuous attention for both application and academic research. Semiconductor-based substrates with SERS activity present more practical applications, ranging from surface science to biological detection because of their lower cost and better biocompatibility compared with noble metals. However, the SERS performance of most semiconductor-based substrates is not significant. Herein, we propose the concept of semiconductor heterojunction-enhanced Raman scattering and design a vertical nanothickness heterojunction of W18O49/monolayer MoS2. As a result, the Raman signals of analyte Rhodamine 6G are detectable even with an ultralow concentration of 10–9 M on W18O49/monolayer MoS2 substrates. The enhancement factor is around 3.45 × 107. We confirmed from experiments and theory that the coupling of these two semiconductor materials could lead to dramatic enhancement of photoinduced charge-transfer processes, which enables giant heterojunction-enhanced Raman scattering.
Y. M. Yang*, F. Kong, M. Z. Li, J. Y. Fan, and T. Qiu*, “Interaction between indium tin oxide nanoparticles and ferricytochrome c: Conformation, redox state, and adsorption scheme”, Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, vol. 213, pp. 64 – 72 (2019).
The conformations and redox states of ferricytochromec, before and after adsorption onto the surface of the in-dium tin oxide (ITO) nanoparticles, are studied to reveal the interaction nature between the cytochromecandthe conducting metal oxide surface. The characterizations with resonance Raman scattering and UV–Vis absorp-tion reveal that the change of pH at moderate ionic strength induces transitions of conformations and redox-states, which suggests that there is intramolecular electron transfer. The conformations of the cytochromecspe-cies are maintained after adsorption onto or collision with the ITO surface, but the redox states change signifi-cantly, and the change depends on the surface structure of the ITO nanoparticle. The adsorption or collisionprocesses aregoverned by the pH-dependentelectrostaticinteractionbetween the proteins and the buffer anionsbound to the ITO surface. This adsorption scenario differs from the convention.
X. Y. Hou, X. G. Luo, X. C. Fan, Z. H. Peng, and T. Qiu*, “Plasmon-coupled charge transfer in WO3−x semiconductor nanoarrays: toward highly uniform silver-comparable SERS platforms”, Physical Chemistry Chemical Physics, vol. 21, iss. 5, pp. 2611 – 2618 (2019).
Transition metal oxide semiconductors have been explored in surface-enhanced Raman scattering (SERS) active substrates, yet their detection sensitivity and enhancement effects are inferior. What's more, the reported fabrication technique ignored the effects of the electromagnetic mechanisms and was far from satisfactory for practical applications. Herein, we report on a convenient nanotechnique to fabricate large-area hexagon plum-blossom-like WO3−x nanoarrays based on aluminum nanobowl array substrates. Localized surface plasmon resonance can be increased via adjusting the time of tungsten magnetron sputtering with H2 annealing treatment. The introduction of a double-switch experiment demonstrates that localized surface plasmon-coupled photoinduced charge transfer can not only increase SERS enhancement comparable to similar silver nanostructures but also implement a low limit of detection below 10−9 M. A triple-switch experiment offers specific rules in the molecular detection of WO3−x semiconductors and important guidance for the fabrication of SERS-active semiconducting platforms.
Q. H. Jing, H. Zhang, H. Huang, X. C. Fan, Y. M. Zhang, X. Y. Hou, Q. Y. Xu, Z. H. Ni*,and T. Qiu*, “Ultrasonic exfoliated ReS2 nanosheets: fabrication and use as co-catalyst for enhancing photocatalytic efficiency of TiO2 nanoparticles under sunlight”, Nanotechnology, vol. 30, no. 18, Article Number: 184001 (2019).
Rhenium disulfide (ReS2) is an interesting kind of transition metal dichalcogenide (TMD) because of its thickness-independent and suitable direct-bandgap structure, which could enable highly efficient solar-energy conversion efficiency. Here, we demonstrate an ultrasonic liquid exfoliation technique in combination with grinding to produce high quality ReS2 nanosheets (NSs) on a large scale. After combination with TiO2 nanoparticles, the co-catalytic performance of TiO2@ReS2 nanocomposites is investigated, which presents dramatically enhanced degradation activity of organic pigments under sunlight illumination in comparison with pure TiO2 nanoparticles. The underlying mechanism of enhanced photocatalytic activity can be attributed to improved separation efficiency of photogenerated electron–hole pairs in TiO2@ReS2 nanocomposites, which is confirmed by photoluminescence analysis and photoelectrochemical measurements. Our results demonstrate that the layered ReS2 NS is a promising two-dimensional supporting platform for photocatalysis and moreover it could also provide a new perspective on TMDs co-catalyst.
B. R. Xu, X. Y. Zhang, Z. Tian, D. Han, X. C. Fan, Y. M. Chen, Z. F. Di, T. Qiu, and Y. F. Mei*, “Microdroplet-guided intercalation anddeterministic delamination towards intelligentrolling origami”, Nature Communications , vol. 10, Article Number: 5019 (2019).