Delicate Manipulation Research Articles

Charge Transfer Excited State Promoted Multiple Resonance Delayed Fluorescence Emitter for High-Performance Narrowband Electroluminescence.

Multiple resonance thermally activated delayed fluorescence (MR-TADF) emitters are promising candidates for narrowband organic light-emitting diodes, but their electroluminescent performance is typically hindered by the slow reverse intersystem crossing rate (kRISC). Herein, we present an effective strategy to introduce a multichannel reverse intersystem crossing (RISC) pathway with large spin-orbit coupling by orthogonally linking an electron-donating unit to the MR framework. Through delicate manipulation of the excited-state energy levels, an additional intersegmental charge transfer triplet state could be "silently" induced without perturbing the MR character of the lowest excited singlet state. The proof-of-concept emitter CzBN3 not only affords 23-fold increase of kRISC compared with its prototypical MR skeleton but also realizes close-to-unity photoluminescence quantum yield, large radiative rate constant, and very narrow emission spectrum. These merits enable high maximum external quantum efficiency (EQEmax) of up to 37.1% and alleviated efficiency roll-off in the sensitizer-free device (EQE1000 = 30.4%), and a further boost of efficiency (EQEmax/1000 = 42.3/34.1%) is realized in the hyperfluorescent device. The state-of-the-art electroluminescent performance validates the superiority of our molecular design strategy.

Unraveling Soft Squeezing Transformations in Time-Variant Elastic Fields

Quantum squeezing, an intriguing phenomenon that amplifies the uncertainty of one variable while diminishing that of its conjugate, may be studied as a time-dependent process, with exact solutions frequently derived from frameworks grounded in adiabatic invariants. Remarkably, we reveal that exact solutions can be ascertained in the presence of time-variant elastic forces, eschewing dependence on invariants or frozen eigenstate formalism. Delving into these solutions as an inverse problem unveils their direct connection to the design of elastic fields, responsible for inducing squeezing transformations onto canonical variables. Of particular note is that the dynamic transformations under investigation belong to a class of gentle quantum operations, distinguished by their delicate manipulation of particles, thereby circumventing the abrupt energy surges commonplace in conventional control protocols.

Conjugating Coumarin with Tetraphenylethylene to Achieve Dual-State Emission for Reversible Mechanofluorochromism and Live Cell Imaging.

Dual-state emission luminogens (DSEgens) are receiving research interest in the construction of multifunctional materials due to their inherent advantage of high emission efficiency in both the molecularly dispersed solution state and the solid state. However, it remains challenging in synthesizing DSEgens via a delicate manipulation of the molecular structures. This work presents an example of bright DSEgen synthesis by tuning the molecular electronic structures and conformations. Three coumarin-tetraphenylethylene (TPE) molecules with a donor-acceptor electronic structure and highly twisting conformations have been synthesized. While compound resulting from direct conjugation of coumarin with a TPE unit shows aggregation-induced emission, compound with an N,N-diaminoethyl modification on the 7-position of coumarin and compound with a further phenyl linker between coumarin and TPE units feature strong dual-state emission. Benefiting from their strong solid emission and twisting conformations, these fluorophores display reversible mechanofluorochromism. Finally, applications for rewritable information storage in the solid state and live-cell imaging in the solution state were demonstrated.

Kirigami-Inspired 3D Printable Soft Pneumatic Actuators with Multiple Deformation Modes for Soft Robotic Applications.

Soft robots have received much attention due to their impressive capabilities including high flexibility and inherent safety features for humans or unstructured environments compared with hard-bodied robots. Soft actuators are the crucial components of soft robotic systems. Soft robots require dexterous soft actuators to provide the desired deformation for different soft robotic applications. Most of the existing soft actuators have only one or two deformation modes. In this article, a new soft pneumatic actuator (SPA) is proposed taking inspiration from Kirigami. Kirigami-inspired cuts are applied to the actuator design, which enables the SPA to be equipped with multiple deformation modes. The proposed Kirigami-inspired soft pneumatic actuator (KiriSPA) is capable of producing bending motion, stretching motion, contraction motion, combined motion of bending and stretching, and combined motion of bending and contraction. The KiriSPA can be directly manufactured using 3D printers based on the fused deposition modeling technology. Finite element method is used to analyze and predict the deformation modes of the KiriSPA. We also investigated the step response, creep, hysteresis, actuation speed, stroke, workspace, stiffness, power density, and blocked force of the KiriSPA. Moreover, we demonstrated that KiriSPAs can be combined to expand the capabilities of various soft robotic systems including the soft robotic gripper for delicate object manipulation, the soft planar robotic manipulator for picking objects in the confined environment, the quadrupedal soft crawling robot, and the soft robot with the flipping locomotion.

Phthalimide based new photocatalysts featured with highly selective photodegradation of azo-dyes and good photocatalytic activity in both homogeneous and heterogeneous systems

• Phthalimide (PI) preferentially photodegrades azo dye in mixture with non-azo dye. • PI shows good photocatalytic activity in homogeneous and heterogeneous system. • Halogenation of PI tunes the photocatalytic performance. • PI with selective photodegradation of dye is promising in environment remediation. Selective degradation of the target pollutants allows delicate manipulation of the environmental remediation process via photocatalysis, and has attracted much attention in recent years. Herein, we report the preparation and photocatalytic behaviors of an organic semiconductor of phthalimide (PI). It is found that PI could effectively degrade the azo-dyes under UV irradiation in either heterogeneous or homogeneous reaction system, which is rarely reported for the photodegradation of the dyes. In comparison, the halogenation of PI has an adverse effect on the photocatalytic activity of corresponding PI derivatives. Moreover, PI is used to photodegrade the mixtures of azo-dyes and non-azo dyes. It is found that PI achieves highly selective photodegradation of the azo-dyes in a heterogeneous reaction system, while its halogenated derivatives exhibit lower selectivity. By contrast, no preferential photodegradation is observed in the homogeneous methanol solution. It is proposed that the regular π-π stacking conjugated structure of the PI based molecules are responsible for the selective photodegradation behaviors. The work offers new approaches for the development of advanced organic molecule photocatalysts with desirable features including selective photodegradation and efficient degradation of dyes in both heterogeneous and homogeneous photocatalysis.

Finch: Prosthetic Arm With Three Opposing Fingers Controlled by a Muscle Bulge.

Forearm amputees can use body-powered hooks and myoelectric hands for their daily activities. The body-powered hooks are suitable for delicate manipulation. However, their appearance is not always preferred by amputees, and a harness to pull a control cable is not easy to wear. Although the myoelectric hands have a natural appearance similar to the human hand and can be intuitively controlled by a myoelectric control system, they are not easy to try out and are heavy. This paper reports on the Finch, a prosthetic arm with three opposing fingers controlled by a muscle bulge. The aim of developing the Finch is to realize a lightweight prosthetic arm that is easy to wear and use. Three opposing fingers are controlled according to the degree of muscle bulge measured with a muscle bulge sensor on the user's forearm caused by muscle contraction. A supporter socket, consisting of a resin socket frame and a fabric supporter, allows easy fitting. A simple design using a linear actuator and 3D-printed parts achieved light weight (330 g) and low cost. Six functional tests and user tests using Southampton Hand Assessment Procedure showed that the Finch had a practical function that could be used in daily activities.

Effective charge transfer regulation for robust photoelectrochemical water splitting

The direct conversion of solar energy to chemical fuels is an important approach to address the world's challenges of sustainable energy, environmental and climate issues owing to the abundant solar energy. Photoectrochemical (PEC) cells as a promising technology by the utilization of solar energy have received much attention for the generation of renewable hydrogen from water splitting on a large scale. However, the efficiency of solar energy conversion into hydrogen is still limited by narrow light absorption, slow charge transfer and sluggish surface reaction kinetics. Great efforts in the regulation of charge transfer have been summarized toward efficient solar-to-chemical energy conversion in this review. Firstly, various photoanodes and photocathodes are been discussed. Then, different strategies such as morphological regulation, heteroatom and defect introduction, heterostructure engineering and cocatalyst incorporation are elaborated to accelerate the charge transfer process and optimize the PEC performance. Finally, the perspectives and comprehensive outlooks on the future regulation of charge transfer are also proposed. This review offers an overview for the rational design and development of the promising photoelectrodes and the delicate manipulation of photogenerated charge transfer in PEC systems for effective solar-to-chemical energy conversion.

Pursuing colloidal diamonds.

The endeavor to selectively fabricate a cubic diamond is challenging due to the formation of competing phases such as its hexagonal polymorph or others possessing similar free energy. The necessity to achieve this is of paramount importance since the cubic diamond is the only polymorph exhibiting a complete photonic bandgap, making it a promising candidate in view of photonic applications. Herein, we demonstrate that due to the presence of an external field and delicate manipulation of its strength we can attain selectivity in the formation of a cubic diamond in a one-component system comprised of designer tetrahedral patchy particles. The driving force of such a phenomenon is the structure of the first adlayer which is commensurate with the (110) face of the cubic diamond. Moreover, after a successful nucleation event, once the external field is turned off, the structure remains stable, paving an avenue for further post-synthetic treatment.

Gastrotomy followed by gastrorrhaphy as a reliable and more physiologic technique for inducing peritoneal adhesion in rats.

this research objective was to develop a new peritoneal adhesion animal model that would lead to adhesions formation in all operated animals, simple and reproducible, associated with maintenance the animal's health. eighteen adult male Wistar rats (Rattus norvegicus) were randomly distributed into three groups: Control Group (anatomical and clinical parameters), Sham Group (delicate manipulation of the stomach and exposure of the peritoneal cavity to ambient air) and Surgery Group (gastrotomy followed by gastrorrhaphy). The animals were analyzed and classificated macroscopically according to two adhesion classification models and differences between groups were considered significant when p<0.05. the six animals in the control group had no peritoneal adhesions, three of the six animals in the sham group had focal peritoneal adhesions, and all animals in the surgery group (gastrotomy followed by gastrorraphy) had firm peritoneal adhesions. All adhesions found were macroscopically quantified and microscopically confirmed, without carrying out a microscopic classification of the adhesions. the new model developed of gastrotomy followed by gastrorrhaphy, proved to be safe and efficient to induce and study peritoneal adhesions.

Extraordinary role of resonant dopant vanadium for improving thermoelectrics in n-type PbTe

Inspired by the bottleneck that the optimization of the dimensionless figure of merit zT is limited by the concept of amorphous limit, impurity-induced band structure distortion independent of phonon properties opens up an effective avenue to significantly enhance room-temperature thermoelectrics of narrow-bandgap materials. In this work, density functional theory calculations confirm the virtual bound state of vanadium at the bottom of the conduction band in n-type PbTe. The effectiveness of the resonant level in enhancing electrical properties not only depends on the electronic structure or scattering mechanism near the chemical potential, but also on the Fermi level. Therefore, a delicate manipulation of the Fermi level is achieved by trace copper substitution to optimize the thermoelectric performance. Furthermore, based on the single parabolic band model and the relaxation time approximation, the dominant term of the transition-metal localized d-electron resonant state in increasing the Seebeck coefficient is clarified in n-type PbTe, which is significantly different from that of the thallium resonant level. More importantly, combined with the mechanism of shortening phonon relaxation time through multi-scale defect sources, the lattice thermal conductivity is drastically reduced. Here, the n-type Pb0.967Cu0.003V0.03Te sample enables an increased peak zT of ∼1.3, as well as the average zTavg of ∼1.1 from 523 to 823 K. The current findings provide a paradigm for the transition-metal resonant states to regulate thermoelectrics.

A Preliminary Study on Grip-Induced Nerve Damage Caused by a Soft Pneumatic Elastomeric Gripper.

Forceps, clamps, and haemostats are essential surgical tools required for all surgical interventions. While they are widely used to grasp, hold, and manipulate soft tissue, their metallic rigid structure may cause tissue damage due to the potential risk of applying excessive gripping forces. Soft pneumatic surgical grippers fabricated by silicone elastomeric materials with low Young’s modulus may offer a promising solution to minimize this unintentional damage due to their inherent excellent compliance and compressibility. The goal of this work is to evaluate and compare the grip-induced nerve damage caused by the soft pneumatic elastomeric gripper and conventional haemostats during surgical manipulation. Twenty-four Wistar rats (male, seven weeks) are subjected to sciatic nerve compression (right hind limb) using the soft pneumatic elastomer gripper and haemostats. A histopathological analysis is conducted at different time-points (Day 0, Day 3, Day 7 and Day 13) after the nerve compression to examine the morphological tissue changes between the rats in the ‘soft gripper’ group and the ‘haemostats’ group. A free walking analysis is also performed to examine the walking function of the rats after recovery from different time points. Comparing the rigid haemostats and soft gripper groups, there is a visible difference in the degree of axonal vacuolar degeneration between the groups, which could suggest the presence of substantial nerve damage in the ‘haemostats’ group. The rats in the haemostats group exhibited reduced right hind paw pressure and paw size after the nerve compression. It shows that the rats tend not to exert more force on the affected right hind limb in the haemostats group compared to the soft gripper group. In addition, the stance duration was reduced in the injured right hind limb compared to the normal left hind limb in the haemostats group. These observations show that the soft pneumatic surgical gripper made of silicone elastomeric materials might reduce the severity of grip-induced damage by providing a safe compliant grip compared to the conventional haemostats. The soft pneumatic elastomer gripper could complement the current surgical gripping tool in delicate tissue manipulation.

Controlling Soft Fluidic Actuators Using Soft DEA-Based Valves

Fluidic soft actuators have been widely used for applications where compliance is desirable – such as in delicate robotic manipulation. As their operation is based on pressurization, fluidic actuators typically rely on bulky, rigid pumps, valves, and pressure regulators for control. This dependence on rigid components hinders the development of compact and fully-soft robots. Soft regulation systems designed for control of these actuators have been recently developed based on soft valves using dielectric elastomer actuators, but precise control has not been achieved. In this work, we leverage these valves to introduce a soft regulation system capable of precise closed-loop position control of a soft hydraulic actuator with multiple controllers. We also achieve open-loop trajectory tracking based on a data-driven model of the fluidic system. Finally, we combine the valve system with wearable strain sensors to create the first teleoperated fluidic circuit where the sensor, actuator, and regulation system are all soft. This work presents control strategies for fluid-driven actuators with soft sensors and regulation systems, showing the potential for future all-soft motion control of soft hydraulic robots.

‘Failed Feminism’

In Vinegar Girl, a 2016 fictional adaptation of The Taming of the Shrew, Anne Tyler exhibits an ambivalent treatment of the female predicaments left by William Shakespeare: while she invests her modern version of Katherina with linguistic and intellectual independence emblematic of female resistance to patriarchal disciplines, she somehow acquiesces in the fixed familial place and the stereotypical images of women in the monolithic patriarchal system. When the novel was introduced into the Chinese mainland in 2017, the Chinese publisher, out of commercial concerns, advertised it as a highly feminist text through the delicate manipulation of the translation of its title and a series of paratextual manoeuvres, to the detriment of the novel’s ambiguous complexities of gender issues. The marketing strategies nevertheless backfired on one of China’s social media platforms and rendered the novel a relatively ‘failed’ feminist text against China’s unique market and media background in the last decade.

Delicate and Independent Manipulation of Dynamic Fluorescence Behavior of Polymer Nanoparticles Based on a Core-Shell Strategy.

Fluorescent polymer nanomaterials with dynamic fluorescence properties hold great potential in many advanced applications, including but not limited to information encryption, adaptive camouflage, and biosensors. The key to improving the application value of materials is to establish an accurate control strategy for dynamic fluorescence behavior. Herein, we develop a core-shell engineering strategy to precisely and independently manipulate the dynamic fluorescence behavior through the shell polymeric matrix. The core-shell fluorescent polymer nanoparticles (CS-FPNPs) are constructed through a sequential process of miniemulsion polymerization and seeded emulsion polymerization. Taking advantage of the core-shell structure, the rigid core matrix ensures the strong initial emission of AIE units, while the photoisomerization behavior of spiropyrane (SP) units is delicately and independently regulated by the rigidness of the shell matrix. Thereby, CS-FPNPs exhibit bright time-dependent reversible dynamic fluorescence behavior under alternating UV/vis irradiation. Benefited from the excellent processability and film formation ability, we have successfully applied CS-FPNPs to dynamic decorative painting, warning labels, and dynamic QR code security. Impressively, the fluorescence manipulation strategy based on core-shell engineering allows the independent regulation of specific luminescent units in complicated emission systems to accurately embody designed emission behavior.

Encapsulation of Co/Co3O4 hetero-nanoparticles within the inner tips of N-doped carbon nanotubes: Engineering Mott-Schottky nanoreactors for efficient bifunctional oxygen electrocalysis toward flexible zinc-air batteries

The development of economical, efficient and durable bifunctional electrocatalysts for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is of paramount importance for the substantial advancement of flexible and rechargeable metal-air batteries. The delicate manipulation of metal/semiconductor heterointerfaces represents a powerful leverage to boost the electrocatalytic performance due to the Mott-Schottky effect. Herein, we demonstrate a typical Mott-Schottky electrocatalyst by ingeniously encasing Co/Co3O4 hetero-nanoparticles within the inner tips of N-doped carbon nanotubes (abbreviated as Co/Co3O4@N-CNTs hereafter) through a facile and scalable hydrogel-bridged pyrolysis strategy. Experimental and theoretical findings collectively manifest that the spontaneous charge redistribution at the Co/Co3O4 heterointerfaces is essential to promote the charge transfer capability, lower down the reaction barriers for oxygen electrocatalysis, and ultimately boost the intrinsic activities. Accordingly, the well-designed Co/Co3O4@N-CNTs exhibit admirable ORR and OER activities and long-term robustness in KOH medium, exceeding the commercial Pt/C and RuO2 benchmarks, respectively. Furthermore, the Co/Co3O4@N-CNTs-assembled flexible all-solid-state zinc-air battery displays a high power density, remarkable rate capability, excellent rechargeablity and outstanding mechanical flexibility even under severe deformations, predicting the great potentials in diverse next-generation wearable electronic devices. The rationale of the construction of Mott-Schottky heterojunctions may provide an innovative and instructive avenue to design diversified energy nanomaterials.

Fluorescence of Single Rhodamine Molecules Near the Surface of Gold

Fluorescent properties of single Rhodamine molecules at different distances to the surface of a high-quality polycrystalline gold film are investigated by the time-correlated single-photon counting technique. The fluorescence lifetime and the fluorescence intensity of the dye molecules as a function of their distance to the gold surface are modeled quantitatively by a classical model for a horizontal electric dipole. The analysis shown herein represents a useful tool to model and further to control molecular fluorescence near complex plasmonic structures, where delicate manipulation of fluorescence emission intensity is of paramount importance.

Chlorobenzenesulfonic Potassium Salts as the Efficient Multifunctional Passivator for the Buried Interface in Regular Perovskite Solar Cells

AbstractThe interfacial properties for the buried junctions of the perovskite solar cells (PSCs) play a crucial role for the further enhancement of the power conversion efficiency (PCE) and stability of devices. Delicate manipulation of the interface properties such as the defect density, energy alignment, perovskite film quality, etc., guarantees efficient extraction and transport of photogenerated carriers. Herein, chlorobenzenesulfonic potassium salts are presented as a novel multifunctional agent to modify the buried tin oxide (SnO2)/perovskite interface for regular PSCs. The increasing number of carbon‐chlorine bonds (CCl) in 2,4,5‐trichlorobenzenesulfonic potassium (3Cl‐BSAK) exhibit efficient interaction with uncoordinated Sn, effectively filling oxygen vacancies in the SnO2 surface. Importantly, synergistic effects of the functional group‐rich organic anions and the potassium ion are achieved for reduced defect density, carrier recombination, and hysteresis. A champion PCE of 24.27% and the open‐circuit voltage (VOC) up to 1.191 V for modified devices are obtained. The unencapsulated devices maintain 80% of their initial PCE after aging at 80 °C for 800 h in the atmosphere and 95% after aging for 100 d. With 3Cl‐BSAK decoration, a high efficiency semitransparent PSC with a PCE of 12.83% and an average visible light transmittance (AVT) over 27% is also obtained.

Use of a Surgical Microscope for Subperichondrial-Subperiosteal Dissection in Preservation Rhinoplasty: Ergonomic Considerations.

SummaryPreservation of anatomical components in rhinoplasty has gained increasing popularity over recent years. Given that elevation of the soft tissue envelope in a continuous subperiochondrial–subperiosteal dissection preserves soft tissues, vessels, nerves, and lymphatics, this procedure may result in faster healing time and less swelling and scarring. However, the technique requires a learning phase and can be challenging to perform because it typically requires meticulous dissection under surgical loupes. The dissection may thus be time-consuming and a burden for surgeons, especially in secondary rhinoplasty cases. Further, the potential risk of musculoskeletal discomfort and injury to the surgeon should not be overlooked; consideration for surgical ergonomics is needed to prevent injuries and enhance surgical performance. To address these issues, we propose the use of a surgical microscope for subperiochondrial–subperiosteal dissection in preservation rhinoplasty. A microscope enables clear visualization of the surgical field and allows surgeons to make precise and delicate manipulation maneuvers. Moreover, it may also enable surgeons to maintain an ideal ergonomic posture and neutral positioning of their joints, thereby reducing physical strain. A surgical microscope may thus be a useful tool for subperiochondrial–subperiosteal dissection by providing clear visualization of the surgical field and improved surgical ergonomics for surgeons.

Fast physical random bit generation of wideband flat chaos signal based on filter feedback

&lt;sec&gt;Chaotic lasers feature wide spectrum and noise-like features, and extensively used in various fields, such as secure communications and random bit generation (RBG). Since the physical RBG using optical chaos was demonstrated first by Uchida et al., the optical chaos has been widely investigated in terms of chaos bandwidth and flatness, which determines the rate and randomness of RBG. Owing to the natural stability of semiconductor lasers, external perturbation is required to generate chaotic signals, such as optical injection, current modulation, and optical feedback. Among them, a semiconductor laser with optical feedback has attracted wide attention because of its simple structure and rich dynamic behaviors. Nonetheless, this configuration suffers the influence of the relaxation oscillation, which results in a limited bandwidth (a few GHz) and an uneven power spectrum. To obtain broad-spectrum chaotic signals, considerable efforts have been made in recent years. However, these solutions are associated with complex structures that require delicate manipulation because multiple parameters should be matched, so the cost of some of these schemes in terms of the system complexity can potentially outweigh the benefits.&lt;/sec&gt;&lt;sec&gt;In this work, we incorporate an optical filter and an amplifier into the feedback loop of a conventional optical feedback system to generate broadband chaotic signals. The effects of the filter detuning frequency and feedback power on the bandwidth and flatness of the chaotic output are investigated experimentally. The experimental results demonstrate that by appropriately adjusting the feedback power and detuning frequency, both the low-frequency components and the high-frequency components of the chaotic output power spectrum can be increased, and the maximum chaotic bandwidth can reach 24.4 GHz with a flatness of 5.7 dB. This phenomenon is attributed to the physical process of beating between the filtered mode and the internal modes of the laser. Furthermore, the optimized chaotic output is processed by retaining the 4 least significant bits and implementing the delayed exclusive-OR (XOR) operation. Our scheme is capable of generating physical random number of the bit rate of 320 Gbit/s, and successfully passes the standard randomness test, i.e. the NIST test (NIST SP 800-22).&lt;/sec&gt;

Manipulation of the halloysite clay nanotube lumen for environmental remediation: a review

The halloysite clay nanotube lumen has shown great application potential in the field of environmental remediation. This relies on delicate manipulation of the clay nanotube lumen and benefits from the unique functionality of the nanotube lumen.