Dual Response Research Articles

Passively Broadband Tunable Dual Circular Dichroism via Bound States in the Continuum in Topological Chiral Metasurface.

Dynamic control for a strong circular dichroism (CD) response is essential in engineering applications such as polarization manipulation, sensing, and imaging. Here, we propose and experimentally demonstrate a broadband tunable dual CD response via bound states in the continuum (BICs) in two-dimensional topologically protected metasurfaces composed of all-dielectric Si chiral grating structures that generate a pair of mixed and degenerated BIC mode and circular dichroic mode (CDM) as an additional degree of freedom in CD manipulation. It is found that a singular CD peak of nearly 100% at 1.6 μm can be achieved by CDM when BIC is hidden under normal incidence, while the CD peak can be split into two in which peak wavelengths can be precisely and linearly tuned over a bandwidth of 180 nm by the incident angle when the BIC mode is excited under oblique incidence. Additionally, dynamic modulation of output polarization states from linear to circular can be arbitrarily achieved at the split CD peaks by controlling the incident angle when asymmetry perturbations on chiral gratings are introduced due to the decoupling of various polarization states at Γ point by BIC to different positions in K space. The proposed chiral grating metasurface exhibits unique angle-sensitive tunable CD spectral characteristics, making it ideal for hyperspectral and spin-selective wavefront shaping, and holds significant promise in various applications such as optical security, angle sensors, chiral lasers, nonlinear filters, and other active chiral optical devices.

CO2/N2 and redox dual-responsive organogels based on ferrocenemethanol and octadecylamine

Herein, we report a CO2/N2 and redox dual-responsive organogel using low molecular mass gelators (LMWGs) of octadecylamine (NC18) and ferrocenemethanol (FcOH). The organogels of NC18-FcOH in cyclohexane have a layered stacking structure and the critical gelling concentration (CGC) is 55 mmol/L. The organogel can be reversibly switched between gel and solution states by CO2 trigger, resulting from the reversible protonation of NC18. Moreover, the organogel can be destroyed by a redox reaction after adding Ce(NH4)2(NO3)6, originating from the oxidization of the ferrocene group in FcOH. Compared with other redox-responsive gelators, complex organic synthesis could be avoided since FcOH is a commercially available compound. The dual responsiveness of the organogel allows for the smart control of the “sol-gel” transition, which has potential applications in functional materials and sensors.

Dual Response Optimization of Ultrasound-Assisted Oil Extraction from Milkfish By-Products using D-Limonene as A Bio-Based Solvent

Dual Response Optimization of Ultrasound-Assisted Oil Extraction from Milkfish By-Products using D-Limonene as A Bio-Based Solvent

Harnessing chemical functionality of xylan hemicellulose towards carbohydrate polymer-based pH/magnetic dual-responsive nanocomposite hydrogel for drug delivery

This study reports a pH/magnetic dual-responsive hemicellulose-based nanocomposite hydrogel with nearly 100 % carbohydrate polymer-based and biodegradable polymer compositions for drug delivery. We synthesized pure Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) using a co-precipitation method, then engineering xylan hemicellulose (XH), acrylic acid, poly(ethylene glycol) diacrylate, and Fe3O4 to synthesize the pH/magnetic dual-responsive hydrogel (Fe3O4@XH-Gel), through graft polymerization on XH with in-situ doping Fe3O4 MNPs initiated by the ammonium persulfate/tetramethylethylenediamine redox system. Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (1H NMR), X-ray diffractometry (XRD), scanning electron microscopy and energy dispersive spectrometer (SEM-EDS), high-resolution transmission electron microscopy (HRTEM), Brunauer-Emmett-Teller (BET), swelling gravimetric analysis, vibrating sample magnetometer (VSM) were employed to analyze the hydrogel's chemical structures, morphologies, pH-responsive behaviors, and magnetic responsiveness characteristics, mechanical and rheological properties, as well as cytotoxicity and biodegradability. The results indicate that the Fe3O4@XH-Gel exhibited excellent dual responsiveness to pH and magnetism. Furthermore, an emphasis was placed on the in-depth analysis of the pH response mechanism. Finally, we utilized this cutting-edge hydrogel to investigate the controlled-release behavior of two model drugs, Acetylsalicylic acid and Theophylline. The hydrogel demonstrated exceptional controlled release attributes, positioning it as a potential carrier for targeted drug delivery, particularly to the gastrointestinal conditions.

Hydrogel Fiber Actuators Prepared by Shell–Core Structure for High-Performance Water/Light Dual Response

Hydrogel Fiber Actuators Prepared by Shell–Core Structure for High-Performance Water/Light Dual Response

Mesoporous Graphene Oxide Nanocomposite Effective for Combined Chemo/Photo Therapy Against Non-Small Cell Lung Cancer.

Lung cancer is the most common cancer worldwide, among which non-small cell lung cancer (NSCLC) accounts for about 80% of all lung cancers. Chemotherapy, a mainstay modality for NSCLC, has demonstrated restricted effectiveness due to the emergence of chemo-resistance and systemic side effects. Studies have indicated that combining chemotherapy with phototherapy, such as photodynamic therapy (PDT) and photothermal therapy (PTT), can enhance efficacy of therapy. In this work, an aminated mesoporous graphene oxide (rPGO)-protoporphyrin IX (PPIX)-hyaluronic acid (HA)@Osimertinib (AZD) nanodrug delivery system (rPPH@AZD) was successfully developed for combined chemotherapy/phototherapy for NSCLC. A pH/hyaluronidase-responsive nanodrug delivery system (rPPH@AZD) was prepared using mesoporous graphene oxide. Its morphology, elemental composition, surface functional groups, optical properties, in vitro drug release ability, photothermal properties, reactive oxygen species production, cellular uptake and cell viability were evaluated. In addition, the in vivo therapeutic effect, biocompatibility, and imaging capabilities of rPPH@AZD were verified by a tumor-bearing mouse model. Aminated mesoporous graphene oxide (rPGO) plays a role as a drug delivery vehicle owing to its large specific surface area and ease of surface functionalization. rPGO exhibits excellent photothermal conversion properties under laser irradiation, while PPIX acts as a photosensitizer to generate singlet oxygen. AZD acts as a small molecule targeted drug in chemotherapy. In essence, rPPH@AZD shows excellent photothermal and fluorescence imaging effects in tumor-bearing mice. More importantly, in vitro and in vivo results indicate that rPPH@AZD can achieve hyaluronidase/pH dual response as well as combined chemotherapy/PTT/PDT anti-NSCLC treatment. The newly prepared rPPH@AZD can serve as a promising pH/hyaluronidase-responsive nanodrug delivery system that integrates photothermal/fluorescence imaging and chemo/photo combined therapy for efficient therapy against NSCLC.

Versatile synthesis of cellulose film with excellent electrothermal/photothermal dual responsiveness by introducing MXene and small molecule self-assembled nanosphere

Plant-derived biomaterials have great application prospects in solving environmental pollution and sustainable resource utilization, but the insufficient mechanical strength and lack of functional responsiveness often limit their further development. Inspired by natural small molecules functionalization, a vacuum-assisted filtration nanofibrillated cellulose (NFC)-based film with excellent antibacterial properties, mechanical strength, and electrothermal/photothermal dual-responsiveness was fabricated. As a natural bioactive molecule, antibacterial cinnamaldehyde (CA) is grafted onto tannic acid (TA) rich in pyrogallols via a small molecule self-assembly strategy, and then co-assembled with zinc acetate (ZA) through ion crosslinking to synthesize the functional TACA@ZA nanospheres. After incorporating the MXene and TACA@ZA, an inorganic-organic 3D network system was established in the NFC matrix through dynamic intermolecular hydrogen bonding and strong ionic cross-linking. The mechanical strength and toughness of hybrid composites are remarkably improved by 83.6 % and 418.9 %, respectively. Due to the synergistic effects of MXene and TACA@ZA, the designed NFC-based film also shows significantly enhanced antibacterial activity, UV-blocking ability, as well as photothermal and electrothermal performance. This bioinspired small molecule functionalization strategy opens an innovative design concept for the fabrication of multirole NFC-based biomaterials, which has great application prospects in the commercial fields of multifunctional adhesives, electronic devices, UV shielding coatings, and antibacterial materials.

Responsive Multi-Arm PEG-Modified COF Nanocomposites: Dynamic Photothermal, pH/ROS Dual-Responsive, Targeted Carriers for Rheumatoid Arthritis Treatment.

Rheumatoid arthritis (RA) is a chronic immune disease characterized by the infiltration of immune cells and the proliferation of fibroblast-like synoviocytes (FLS) at the joint site, leading to inflammation and joint destruction. However, the available treatment options targeting both inflammatory and proliferative FLS are limited. Herein, this work presents three covalent organic frameworks (COFs) photothermal composite systems modified with multi-armed polyethylene glycols (PEG) for the treatment of RA. These systems exhibit a dual response under low pH and high reactive oxygen species (ROS) conditions at the site of inflammation, with a specific focus on delivering the protein drug ribonuclease A (RNase A). Notably, molecular docking studies reveal the interaction between RNase A and NF-κB p65 protein, and Western blotting confirm its inhibitory effect on NF-κB activity. In vitro and in vivo experiments verify the significant reduction in joint swelling and deformities in adjuvant-induced arthritis (AIA) rats after treatment with RNase A delivered by multi-armed PEG-modified COF ligands, restoring joint morphology to normal. These findings underscore the promising therapeutic potential of COFs for the treatment of RA, highlighting their unique capabilities in addressing both inflammatory and proliferative aspects of the disease and expanding the scope of biomedical applications for COFs.

Tb3+‐Doped Ca3Ga4O9 Phosphors with Color‐Tunable Photoluminescence and Non‐Pre‐Irradiation Mechanoluminescence for Multimodal Applications

AbstractMaterials that can emit light under optical/mechanical stimulation are usually called photoluminescent/mechanoluminescent (PL/ML) materials. PL materials are used in diverse fields for half a century. While, ML materials have burst out in the last two decades, and now are showing great application potential in the fields of anti‐counterfeiting, information storage, and stress imaging. It is of great significance to explore new luminescent materials with PL and ML dual response. In this study, Tb3+‐doped Ca3Ga4O9 phosphors with color‐tunable PL and non‐pre‐irradiation ML properties are reported. Ca3Ga4O9 exhibits a broadband blue emission centering at 425 nm, which originates from the 4T2‐4A2 transition of electrons in d orbits of Ga3+. Due to the energy transfer from host to Tb3+, color‐tunable emission from blue to cyan, and ultimately to green can be realized by increasing the concentration of Tb3+. Particularly, ML is seen from Ca3Ga4O9:Tb3+ under grinding and from the Ca3Ga4O9:Tb3+/PDMS film under bending or stretching originated from the triboelectric mechanism. The non‐pre‐irradiation ML behavior is evidenced by the contrast thermoluminescence (TL) experiments. This study not only provides a new candidate toward multi‐purpose luminescent applications, but also demonstrates a good case in which the triboelectric effect can efficiently trigger the non‐pre‐irradiation ML behavior.

Odd-even symbol dispersion pre-compensation technique utilizing interleaved dual-FIR filters in IM-DD systems.

An interleaved odd and even samples electrical dispersion pre-compensation (pre-EDC) scheme with low complexity is proposed to alleviate the severe distortions caused by frequency-selective fading due to chromatic dispersion (CD) in the intensity-modulation and direct-detection (IM-DD) optical transmission systems. This scheme utilizes training-based interleaved dual finite impulse response (FIR) filters for odd and even samples pre-compensation, respectively, referred to as training-based ID FIRs-pre-EDC. Additionally, a Tx and Rx side joint scheme is proposed to enhance the performance of the training-based ID FIRs-pre-EDC by implementing the efficient reduced state maximum likelihood sequence estimation (RS-MLSE) at the receiver side. Experimental validations in a C-band 56 Gbit/s PAM-4 80 km standard single-mode fiber (SSMF) transmission system show that the training-based ID FIRs-pre-EDC achieves over 0.95 dB receiver sensitivity improvement at the 7% hard-decision forward error correction (HD-FEC) threshold compared to traditional FIR-pre-EDC schemes. Employing the proposed joint scheme obtains ∼3 dB receiver sensitivity gain at the 7% HD-FEC threshold compared with only implementing training-based ID FIRs-pre-EDC at the transmitter side. These results indicate the potential and feasibility of the proposed schemes in optical interconnects.

Design of a low profile and ultraminiaturized frequency selective surface with dual band-stop response

In this paper, a miniaturized dual-band frequency selective surface (FSS) for electromagnetic shielding applications is presented. The FSS unit cell provides band-stop response at the resonant frequencies of 0.95 GHz and 2.52 GHz. The FSS element is constructed by employing convoluted metal stripes that are positioned on both sides of the substrate. The proposed configuration enhances the electrical length of the resonator while maintaining its physical dimensions. Moreover, the unit cell of the FSS exhibits rotational symmetry, which enables polarization independent operation. The designed FSS structure demonstrates excellent miniaturization characteristics, with a cell size and thickness of 0.019 λ0 × 0.019 λ0, and 0.00048 λ0, respectively. The cell size and thickness are calculated at the lower resonating frequency of 0.95 GHz. In addition, the stability of the proposed FSS structure is observed for both the TE and TM polarizations across an incident angle range of 0° to 80°. The resonating behavior of the structure is elucidated with the help of electric field and surface current distribution. Experimental verification of the dual-band FSS is conducted through the fabrication of a prototype on a FR4 substrate. The measured transmission coefficients are in good agreement with the simulated response for both TE and TM modes. Compared with the dual-band FSSs previously reported, the proposed FSS has the significant advantages of low profile and miniaturization.

Nonlinear optical absorption of Sb2Se3: Dual response and [Sb4Se6]n ribbon orientation dependence

The nonlinear optical (NLO) absorption response of Sb2Se3 polycrystalline film was systemically studied in this work. Both saturable absorption (SA) and reverse satuarable absorption (RSA) are found in Sb2Se3 polycrystalline film with short pulse and long pulse laser, respectively. The transient absorption spectrum of Sb2Se3 reveal the origin of dual NLO absorption response from the view of carrier dynamics. The dispersion of NLO absorption response of Sb2Se3 and its substrate dependence were also investigated in this work. By simulation of open aperture Z-scan data under the femtosecond laser excitation, the NLO absorption coefficient β and absorption cross section difference ∆σbetween ground state and excited state were calculated in spectral region of 700⁓860 nm. The NLO absorption response in these film samples were not only tuned by the excitation wavelength but also dependent on laser pulse width and their substrate. The wavelength-tailored, pulse width-dependent and substrate-dependent NLO properties allow them to be potentially applied in the field of photonics.

Two-response surface design optimization of carboxylated CNCs with super high thermal stability and dye removal capability

Discharging wastewater from industrial dyeing and printing processes poses a significant environmental threat, necessitating green and efficient adsorbents. Cellulose nanocrystals (CNCs) have emerged as a promising option for dye adsorbing. However, the industrial production and commercialization of CNCs still faced low yield, time-consuming, and uneco-friendly. In this study, we proposed a facile hydrochloric/maleic acid (HCl/C4H4O4) hydrolysis method to synthesize carboxylated CNCs using Box-Behnken design and dual response surface design, which can systematically investigate the effect of experimental factors (temperature, time and HCl/C4H4O volume ratio) on the final products. The rod-liked carboxylated CNCs gave the highest yield of 90.50 %, maximum carboxyl content of 1.29 mmol/g, and efficient dye removal ratio of 91.5 %. Furthermore, compared to CNCs obtained by commonly sulfuric acid hydrolysis way (CNCs-S) with a Tmax of 242.6 °C, the CNCs extracted at 5 h exhibited significantly improved thermal stability with Tmax reaching 351.2 °C. The enriched carboxyl content and excellent thermal stability show potential wastewater treatment applications under harsh conditions.

Traditional Chinese Medicine Integrated Multifunctional Responsive Core-Shell Microneedles for Dermatosis Treatment.

Microneedles have demonstrated value in targeted treatment of dermatosis. Current investigation aims to enhance the functions and optimize substance delivery to improve therapeutic effects. Here, we present innovative shell-core microneedles with light-pH dual responsiveness for spatiotemporal sequential release of multiple Chinese herb drugs to treat scleroderma. By using a stepwise template-assisted method, we effectively prepare a hydrogel-based core layer containing polydopamine-MXene (P-MXene) loaded with triptolide (TP), and a shell layer composed of polyvinyl alcohol (PVA) encapsulating paeoniflorin (Pae). P-MXene can adsorb the sparingly soluble TP to ensure its encapsulation efficiency and contribute to the synergistic photothermal effect benefitting from its excellent photothermal conversion ability. Besides, PVA can rapidly dissolve upon microneedle piercing into the skin and quickly release the anti-inflammatory and detoxifying Pae, establishing a favorable low-acid subcutaneous environment. In response to pH changes and near-infrared effects, TP is sustainably released from P-MXene and delivered through the swollen pores of the hydrogel. On the basis of these characteristics, we demonstrate that these microneedles could effectively reduce profibrotic key cytokines interleukin-1β and transforming growth factor-β, thereby reducing collagen deposition and decreasing epidermal thickness, ameliorating skin fibrosis and capillary lesion in scleroderma mouse models. These findings highlight the important clinical potential of these microneedles in the treatment of skin diseases.

Abstract B025: A genome-wide CRISPR screen identifies synthetic lethality of double-stranded RNA with BRCA1 loss

Abstract Double-stranded RNAs (dsRNAs) are potent immunostimulatory nucleic acids of viral origin but also physiologically produced by mammalian cells. Recent studies demonstrated that elevating dsRNA levels, either exogenously through dsRNA mimetics like Polyinosinic-polycytidylic acid (pI:C) or endogenously through epigenetic modulation of retroviral elements, can elicit anticancer effects. In response to dsRNA, cells elicit a dual response consisting in Interferon (IFN) production and translational shutdown associated, in some cells, with cell death. These two responses are linked in a feed-forward loop in which induced cytokines themselves enhance dsRNA sensing by the death-inducing pathway, complicating our understanding of the cell-intrinsic mechanisms at play. The 2',5'-oligoadenylate synthetase (OAS)-RNASEL system is widely thought to be the main responsible for dsRNA-induced cell death, but it remains unclear how its activity leads to cell death. To elucidate these mechanisms, we decided to minimize the impact of interferon modulation by studying dsRNA-induced death in interferon-saturated conditions. We performed a genome-wide CRISPR screen for factors involved in dsRNA-induced death in our interferon-saturated conditions in HT29 cells. Pathway enrichment analysis of screen hits revealed that RNA surveillance, RNA Polymerase II Transcription Initiation, Mitochondrial translation and respiratory chain and DNA Repair genes have a protective role against dsRNA increase. In particular, we identifiedBRCA1 but not BRCA2 as a candidate hit. The differential sensitivity of BRCA1-KO cells was subsequently validated in cloncal populations. Ongoing research is aimed at validating this interaction in vivo models. Our work shed light on potential new mechanisms involved in dsRNA dependent cell death, revealing a connection with DNA damage and BRCA1. If confirmed, these findings may pave the way for the use of dsRNA mimetics, possibly in conjunction with immune checkpoint inhibitors, in the treatment of BRCA1-mutated tumors. Citation Format: Luca Mazzarella, Deborah Trastulli, Sara Galavotti, Gianluca Vozza, Veronica Pinamonti, Nunzia Zagaria. A genome-wide CRISPR screen identifies synthetic lethality of double-stranded RNA with BRCA1 loss [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Expanding and Translating Cancer Synthetic Vulnerabilities; 2024 Jun 10-13; Montreal, Quebec, Canada. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(6 Suppl):Abstract nr B025.

Ultralow-Power Single-Sensor-Based E-Nose System Powered by Duty Cycling and Deep Learning for Real-Time Gas Identification.

This study presents a novel, ultralow-power single-sensor-based electronic nose (e-nose) system for real-time gas identification, distinguishing itself from conventional sensor-array-based e-nose systems, whose power consumption and cost increase with the number of sensors. Our system employs a single metal oxide semiconductor (MOS) sensor built on a suspended 1D nanoheater, driven by duty cycling─characterized by repeated pulsed power inputs. The sensor's ultrafast thermal response, enabled by its small size, effectively decouples the effects of temperature and surface charge exchange on the MOS nanomaterial's conductivity. This provides distinct sensing signals that alternate between responses coupled with and decoupled from the thermally enhanced conductivity, all within a single time domain during duty cycling. The magnitude and ratio of these dual responses vary depending on the gas type and concentration, facilitating the early stage gas identification of five gas types within 30 s via a convolutional neural network (classification accuracy = 93.9%, concentration regression error = 19.8%). Additionally, the duty-cycling mode significantly reduces power consumption by up to 90%, lowering it to 160 μW to heat the sensor to 250 °C. Manufactured using only wafer-level batch microfabrication processes, this innovative e-nose system promises the facile implementation of battery-driven, long-term, and cost-effective IoT monitoring systems.

Dual fluorescence response of calix[4]arene-1,8-naphthalimide derivatives towards Hg(II) /Cr(VI) and their antimicrobial studies of transparent biofilms with hyaluronic acid

In this study, 4-sulfo-1,8-naphthalimide calixarene of derivatives were prepared (3 and 4) then transparent biofilms of the Ag salts of these compounds were formed in the presence of hyaluronic acid (HA), and antimicrobial properties were investigated. In chemosensor studies, the sensing ability behavior of 3 and 4 towards some cations and anions was investigated by fluorescence spectroscopy. It was observed that the prepared chemosensors show selectivity towards Hg(II) and Cr(VI). Ligand-ion interaction occurs according to the photo-induced electron transfer (PET) mechanism. The stoichiometric ratio was calculated by using Stern-Volmer plot method and binding constant Ksv values were found as 5.2 × 107 M−1 and 5.5 × 107 M−1 for 3-Hg(II) and 4-Hg(II) complexes, respectively and 4.0 × 107 M−1 and 4.3 × 107 M−1 for 3-Cr(VI) and 4-Cr(VI) complexes. The detection limits of the complexes of 3-Hg(II) and 4-Hg(II) are 6.35 × 10−12and 6.81 × 10−12, while those of 3-Cr(VI) and 4-Cr(VI) are 1.41 × 10- 11and 8.37 × 10−12, respectively. As a result of the antimicrobial test performed with these compounds, it was observed that the most effective material was HA-3Ag, which showed a significant antibacterial effect against Sarcina lutea (S. lutea) at a minimum inhibitory concentration (MIC) value of 0.097 mg/mL.

Dynamic covalent Fe3O4 nanoparticles for dual-responsive Pickering emulsions triggered by pH and magnetism

In this study, we successfully synthesized silica coated Fe3O4 nanoparticles (Fe3O4@SiO2 NPs) and further animated their surface to create amino modified Fe3O4@SiO2 (Fe3O4@SiO2-NH2) NPs. By taking advantage of the pH-responsive dynamic (covalent) imine bond between the hydrophilic Fe3O4@SiO2-NH2 NPs and the hydrophobic cinnamaldehyde molecule (R), we developed dynamic covalent Fe3O4@SiO2 (Fe3O4@SiO2-R) NPs with switching wettability. These NPs were then utilized to form Pickering emulsions, and whose stability and pH/magnetic response were thoroughly investigated. As the NPs concentration in the emulsion increased, the emulsion stability initially improved but then subsequently slightly decreased. Emulsifiers exhibited emulsifying effect on various oil phases, with paraffin oil demonstrating the best effect. By adding Hydrochloric acid to the emulsion, we successfully broke the imine bond at a pH value of 2.8, resulting in demulsification. Applying a magnetic field also achieved demulsification. After five cycles of pH or magnetic response-induced emulsification and demulsification, a stable Pickering emulsion could still be obtained. Stimuli-responsive Pickering emulsions have been extensively studied, but there is limited research on double-responsive Pickering emulsions. This study presents a novel design of Pickering emulsions with pH/magnetic dual responsiveness, offering great potential for oil-water separation applications.

A novel asymmetric tri-stable piezoelectric vibration energy harvester for low-orbit vibration energy harvesting enhancement

This study introduces an innovative asymmetric tri-stable piezoelectric vibration energy harvester (ATPVEH) augmented with an elastic base (EB), aimed at optimizing energy capture from low-orbit vibrations. This design incorporates a uniquely configured asymmetric tri-stable piezoelectric cantilever beam, positioned within a U-shaped block that is further enhanced by an elastic base. A strategically placed spring (kf)–mass (Mf) system, situated between the U-shaped block and the constrained end of the beam, significantly boosts the vertical displacement of the beam during vibrational events. We developed a dynamic model for the ATPVEH+EB utilizing Lagrange’s equations, exploring the impact of various factors—including the asymmetry of the potential well, the stiffness of the elastic base, the mass of the spring–mass system, and the load resistance—on the system’s nonlinear dynamic responses. Our findings indicate that the ATPVEH+EB facilitates more efficient energy harvesting from low-orbit vibrations, demonstrating dual response peaks across its operational frequency spectrum. Notably, the displacement and output voltage amplitudes of the ATPVEH+EB can be enhanced by increasing mf or decreasing kb, whereas the peak output power transitions toward a lower frequency range as the load resistance escalates. Both theoretical analyses and numerical simulations corroborate the ATPVEH+EB’s superior performance in harvesting energy within low-orbit vibrational environments.

A cellulose nanocrystal-based dual response of photonic colors and fluorescence for sensitive benzene gas detection

Benzene, as a common volatile organic compound, represents serious risk to human health and environment even at low level concentration. There is an urgent concern on visualized, sensitive and real time detection of benzene gases. Herein, by doping Fe3+ and graphene quantum dots (GQDs), a cellulose nanocrystal (CNC) chiral nematic film was designed with dual response of photonic colors and fluorescence to benzene gas. The chiral nematic CNC/Fe/GQDs film could respond to benzene gas changes by reversible motion. Moreover, chiral nematic film also displays reversible responsive to humidity changes. The resulting CNC/Fe/GQDs chiral nematic film showed excellent response performance at benzene gas concentrations of 0–250 mg/m3. The maximal reflection wavelength film red shifted from 576 to 625 nm. Furthermore, structural color of CNC/Fe/GQDs chiral nematic film change at 44 %, 54 %, 76 %, 87 %, and 99 % relative humidity. Interestingly, due to the stability of GQDs to water molecules, CNC/Fe/GQDs chiral nematic film exhibit fluorescence response to benzene gas even in high humidity (RH = 99 %) environment. Besides, we further developed a smartphone-based response network system for quantitively determinization and signal transformation. This work provides a promising routine to realize a new benzene gas response regime and promotes the development of real-time benzene gas detection.