Biohybrid micro- and nanorobots are integrated tiny machines from biological components and artificial components. They can possess the advantages of onboard actuation, sensing, control, and ...implementation of multiple medical tasks such as targeted drug delivery, single-cell manipulation, and cell microsurgery. This review paper is to give an overview of biohybrid micro- and nanorobots for smart drug delivery applications. First, a wide range of biohybrid micro- and nanorobots comprising different biological components are reviewed in detail. Subsequently, the applications of biohybrid micro- and nanorobots for active drug delivery are introduced to demonstrate how such biohybrid micro- and nanorobots are being exploited in the field of medicine and healthcare. Lastly, key challenges to be overcome are discussed to pave the way for the clinical translation and application of the biohybrid micro- and nanorobots.
The occurrence of synthetic and natural hormones in an aqueous environment poses significant risks to humans because of their endocrine-disrupting activity. Autonomous self-propelled and remotely ...actuated nano/microrobots have emerged as a new field that encompasses a wide range of potential applications, including sensing, detection and elimination/degradation of emerging pollutants. In this work, we develop programmable polypyrrole-based (PPy, outer functional layer) microrobots incorporated with a Pt catalytic layer and paramagnetic iron nanoparticles (Fe3O4) to provide self-propulsion and a magnetic response for the highly efficient removal of oestrogenic pollutants. As the pH of the tested water alters, the surface charge of PPy/Fe3O4/Pt microrobots gradually changes, leading to affinity modulation. As microrobots move inside the solution, they collect oestrogen fibres and subsequently weave macroscopic webs on the surface. Our results suggest that motion-controllable microrobots with adjustable surface chemistry could provide a suitable platform for the highly efficient removal of hormonal pollutants.Microrobots are usually too small to contain traditional computing substrates that could control their behaviour. Dekanovsky and colleagues have developed a microrobot swarm that removes hormonal pollutants when it senses a chemical signal in its environment.
The adjustable structures and remarkable physicochemical properties of 2D monoelemental materials, such as silicene and germanene, have attracted significant attention in recent years. They can be ...transformed into silicane (SiH) and germanane (GeH) through covalent functionalization via hydrogen atom termination. However, synthesizing these materials with a scalable and low‐cost fabrication process to achieve high‐quality 2D SiH and GeH poses challenges. Herein, groundbreaking 2D SiH and GeH materials with varying compositions, specifically Si0.25Ge0.75H, Si0.50Ge0.50H, and Si0.75Ge0.25H, are prepared through a simple and efficient chemical exfoliation of their Zintl phases. These 2D materials offer significant advantages, including their large surface area, high mechanical flexibility, rapid electron mobility, and defect‐rich loose‐layered structures. Among these compositions, the Si0.50Ge0.50H electrode demonstrates the highest discharge capacity, reaching up to 1059 mAh g−1 after 60 cycles at a current density of 75 mA g−1. A comprehensive ex‐situ electrochemical analysis is conducted to investigate the reaction mechanisms of lithiation/delithiation in Si0.50Ge0.50H. Subsequently, an initial assessment of the c‐Li15(SixGe1‐x)4 phase after lithiation and the a‐Si0.50Ge0.50 phase after delithiation is presented. Hence, this study contributes crucial insights into the (de)lithiation reaction mechanisms within germanane‐silicane alloys. Such understanding is pivotal for mastering promising materials that amalgamate the finest properties of silicon and germanium.
2D materials with compositions Si0.25Ge0.75H, Si0.50Ge0.50H and Si0.75Ge0.25H, are synthesized a simple and efficient chemical exfoliation of their Zintl phases. Among these, the Si0.50Ge0.50H electrode displays the most superior performance, boosting a discharge capacity of 1059 mAh g−1 following 60 cycles at a current density of 75 mA g−1. A comprehensive ex‐situ electrochemical analysis is performed to study the reaction mechanisms of lithiation/delithiation.
Dopant levels in layered compound InSe have considerable potential in optoelectronic devices. Dopant‐induced trap states are essential in determining the optoelectrical properties of semiconductors. ...However, detailed studies of the persistent photoconductivity (PPC) and related mechanism in doped InSe are still not available. Here, the dependence of excitation energy on the shallow donor level caused by the dopants (Ge, Sn) in InSe is systematically investigated. Notably, prolonged decay time originates from extrinsic Ge, Sn dopants and these doping‐assisted states improve the optoelectrical performance of pristine InSe. Those photogenerated carriers are trapped in the Ge, Sn shallow impurities states, which are long‐lived enough to be extracted into Au contacts before annihilation. This renders Ge‐, Sn‐doped InSe photoconductive gain and maximized photocurrent. Sn‐doped InSe single crystal device can achieve a maximum responsivity of around 1.7 × 106 A W−1 under red light and detectivity of 6.18 × 1013 Jones. In addition, Hall measurements identify the carrier concentration and the Hall mobility of pristine InSe is significantly changed by Ge and Sn dopants. It is demonstrated that doping Ge, Sn atoms is responsible for the obvious photoconductivity and beneficial for the high‐performance photodetector, offering intriguing opportunities for novel holographic memory applications.
For the first time, a systematic study of the excitation energy dependence of persistent photoconductivity in Ge‐, Sn‐doped InSe single crystal is performed. Ge and Sn dopants are responsible for shallow donor level in the pure InSe, which contributes to the relaxation of photoconductivity. Optoelectronic measurements reveal the potential mechanism of dopant‐assisted improved optoelectrical performance.
Urinary‐based infections affect millions of people worldwide. Such bacterial infections are mainly caused by Escherichia coli (E. coli) biofilm formation in the bladder and/or urinary catheters. ...Herein, the authors present a hybrid enzyme/photocatalytic microrobot, based on urease‐immobilized TiO2/CdS nanotube bundles, that can swim in urea as a biocompatible fuel and respond to visible light. Upon illumination for 2 h, these microrobots are able to remove almost 90% of bacterial biofilm, due to the generation of reactive radicals, while bare TiO2/CdS photocatalysts (non‐motile) or urease‐coated microrobots in the dark do not show any toxic effect. These results indicate a synergistic effect between the self‐propulsion provided by the enzyme and the photocatalytic activity induced under light stimuli. This work provides a photo‐biocatalytic approach for the design of efficient light‐driven microrobots with promising applications in microbiology and biomedicine.
Biohybrid enzyme/photocatalyst‐based microrobot structure for the efficient removal of a bacterial biofilm is presented. TiO2 nanotube bundles are decorated with CdS nanoparticles and enzyme urease. This design provides a strategy for developing advanced photoresponsive microrobots with improved catalytic activity, offering great potential for the future applications of micromachines.
Understanding the stability limitations and defect formation mechanisms in 2D magnets is essential for their utilization in spintronic and memory technologies. Here, defects in mono‐ to multilayer ...CrSBr are correlated with structural, vibrational, and magnetic properties. Resonant Raman scattering is used to reveal distinct vibrational defect signatures. In pristine CrSBr, it is shown that bromine atoms mediate vibrational interlayer coupling, allowing for distinguishing between surface and bulk defect modes. Environmental exposure is shown to cause drastic degradation in monolayers, with the formation of intralayer defects. This is in contrast to multilayers that predominantly show bromine surface defects. Through deliberate ion irradiation, the formation of defect modes is tuned: these are strongly polarized and resonantly enhanced, reflecting the quasi‐‐1D electronic character of CrSBr. Strikingly, pronounced signatures of spin‐phonon coupling of the intrinsic phonon modes and the ion beam‐induced defect modes are observed throughout the magnetic transition temperature. Overall, defect engineering of magnetic properties is possible, with resonant Raman spectroscopy serving as a direct fingerprint of magnetic phases and defects in CrSBr.
Strategies for defect engineering and the stability of the 2D magnetic semiconductor CrSBr are explored. Raman spectroscopy is a direct fingerprint of defect modes and the magnetic phase diagram in CrSBr. In the presence of magnetic correlations, pronounced spin‐phonon coupling of bulk phonon and defect modes are observed, providing a pathway to engineer and probe magnetic properties in CrSBr.
All-Solid-State Batteries (ASSBS) are considered as one of the mesmerizing technologies for next-generation energy storage with its inherent safe nature. The versatility of nanomaterials can roadmap ...to the high power/energy storing ASSBs for transferable, bendable, foldable electronics, transportation, and grid-scale energy storage. The most challenging part of designing a comprehensive-nanoscale ASSB assembly, is the down scaling of the particle size of solid electrolyte, upholding its super ionic conductivity. In this context, materials with nanoscale-sized structural features and a large electrochemically active surface can change the paradigm for energy storage that transpire manifold improvement in power and cycle life characteristics. This review primarily provides an outlook on recent progress in the application of the concept of ‘nano’ for energy harvesting in different dwellings of ASSB assemblies. The review also deliberate successful strategies for the exploitation of nanomaterials deployable at the most challenging solid-solid interfaces of ASSBs. Attention is focused on the importance of designing ‘nanoscale particle articulated’, electrode-solid electrolyte interfaces and their aspects in lithium-ion movements.
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•Miniaturization and exploration of novel aspects of nano in the framework of research in all-solid-state batteries.•Importance of nano in all solid-state-battery assembly.•Design of nano cathode and micro/nano electrolyte interface in all-solid-state batteries.•New perspective and directions in all-solid-state batteries.
A major challenge for the development of all-solid-state lithium-ion batteries (ASS-LIBs) relay on the development of an ideal electrolyte material and solving the interfacial issues at the ...electrode-electrolyte interface. Nano-crystalline lithium lanthanum titanate (LLTO) and lithium iron phosphate-carbon (LFP/C) has been prepared as electrolyte and cathode material for a solid-state lithium ion cell (LIBs). Prepared lithium lanthanum titanate, lithium iron phosphate-carbon and the composite powders were subjected to structural, optical, morphological and electrochemical characterizations. The high ionic conductivity of lithium lanthanum titanate (1.06 × 10−4), carbon coated lithium iron phosphate (5.01 × 10−5) and their interface (6.00 × 10−5) designate the pertinence of their full cell configurations. The full cell assembly has been characterized electrochemically to evaluate the performance of the interface. The assembled ASSBs show cyclability up to 55 initial cycles, with the nano-LLTO/LFP-C interface. The line scan analysis has been performed to identify the cation movement and accumulation of ions towards and across the cathode-electrolyte interface after cycling. The present study provides new direction and methodology for the detailed interface analysis across the nano-electrode- nano-solid electrolyte layer in all solid-state assemblies.
Synopsis: Investigation on ionic migration and interfacial phenomena in nano-LLTO-LFP/C. Display omitted
•Preparation of LLTO, LFP/C nano ceramics with optimized structures and ordered diffraction pattern.•Electrochemical investigation of the LLTO-LFP/C interface in all Solid State assembly.•Study of ionic movements across the LLTO-LFP/C interface using Line scan analysis for the first time.
Abstract Understanding the stability limitations and defect formation mechanisms in 2D magnets is essential for their utilization in spintronic and memory technologies. Here, defects in mono‐ to ...multilayer CrSBr are correlated with structural, vibrational, and magnetic properties. Resonant Raman scattering is used to reveal distinct vibrational defect signatures. In pristine CrSBr, it is shown that bromine atoms mediate vibrational interlayer coupling, allowing for distinguishing between surface and bulk defect modes. Environmental exposure is shown to cause drastic degradation in monolayers, with the formation of intralayer defects. This is in contrast to multilayers that predominantly show bromine surface defects. Through deliberate ion irradiation, the formation of defect modes is tuned: these are strongly polarized and resonantly enhanced, reflecting the quasi‐‐1D electronic character of CrSBr. Strikingly, pronounced signatures of spin‐phonon coupling of the intrinsic phonon modes and the ion beam‐induced defect modes are observed throughout the magnetic transition temperature. Overall, defect engineering of magnetic properties is possible, with resonant Raman spectroscopy serving as a direct fingerprint of magnetic phases and defects in CrSBr.
Efficient electrocatalysts for the hydrogen evolution reaction (HER) in alkaline electrolytes can ensure both durability and safety in electrolysis devices. The synergistic integration of ...metal-organic frameworks and two-dimensional materials holds promise for advancing electrocatalytic performance. Herein, we hybridized V2C MXene and the cobalt-based imidazolate zeolitic framework (ZIF-67) by an in-situ precipitation method and investigated its electrocatalytic properties for HER in 1 M KOH solution. Characterization unveiled the successful intercalation of ZIF-67 within the layers of V2C MXene nanosheets. The resulting V2C/ZIF-67 hybrid achieves a good current density of 10 mAcm−2 at a modest overpotential of 197 mV vs RHE and a Tafel slope of 76 mVdec−1. Significantly, the hybrid material shows excellent stability with a minor overpotential loss of 5.5 mV, whereas the Pt/C-20% exhibits a more pronounced loss of 15.3 mV after 12 h of chronopotentiometry. Capitalizing on ZIF-67's substantial active surface and exceptional electrical conductivity of V2C MXene, hybrid material enables the fast transfer of charges and ions across the interface, culminating in its superior electrocatalytic prowess.
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•A facile strategy was developed to synthesize V2C/ZIF-67 heterostructure.•The intercalation of ZIF-67 between V2C nanosheets prevented the aggregation.•V2C/ZIF-67 shows outstanding electrocatalytic performance towards HER in KOH.•The synergic effects enable V2C/ZIF-67 with superior electrocatalytic activity.
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