Tyndall National Institute

The data presented in this article supports the research publication “A data-driven standardised generalisable methodology to validate a large energy performance Certification dataset: A case of the application in Ireland” by Raushan et al. [1]. It provides the filtered Energy Performance Certificate (EPC) database for residential buildings in Ireland after applying rigorous data validation methods to remove erroneous entries, and outliers. EPCs contain valuable information about building energy efficiency and characteristics. The raw EPC database for Ireland is publicly accessible but contains over 1 million unfiltered entries with inconsistent and erroneous values that can skew analysis. This processed dataset enhances the quality and robustness of the EPC data for use in building stock modelling and research. The data is openly available in .CSV format along with the methodology used for processing the raw database, published in full Python scripts. Supporting notes and metadata explain the filtering process, experimental design, and content of 211 variables across four categories: Informational, form, envelope, and system. By publishing this standardised data-driven filtered EPC dataset, this research enables stakeholders, non-expert and expert alike, to leverage this higher quality input for characterising the Irish housing stock.

Graphene nanoribbons (GNRs) have emerged as promising candidates for nanoelectronic devices due to their unique electronic and transport properties. In this study, we investigate the impact of passivation on cove-edge graphene nanoribbon (CGNR) using both cadmium (Cd) and hydrogen (H) atoms. Through a comprehensive density functional theory (DFT) analysis coupled with non-equilibrium Green’s function (NEGF) simulations, we explore the electronic transport properties and device behavior of these passivated CGNRs. Our results reveal a distinctive semiconductor-to-metal transition in the electronic properties of the Cd-passivated CGNRs. This transition, induced by the interaction between Cd atoms and the GNR edges, leads to a modulation of the bandstructure and a pronounced shift in the conductance characteristics. Interestingly, the Cd-passivated CGNR devices exhibit negative differential resistance (NDR) with remarkably high peak-to-valley current ratios (PVCRs). NDR is a phenomenon critical for high-speed switching, enables efficient signal modulation, making it valuable for nanoscale transistors, memory elements, and oscillators. The highest PVCR is measured to be 53.7 for Cd-CGNR-H which is x10 and x17 times higher than strained graphene nanoribbon and silicene nanoribbon respectively. These findings suggest the promising potential of passivated CGNRs as novel components for high-performance nanoelectronic devices.

Carbon dots (CDs) are small-sized, spherical nanomaterials presenting amorphous carbon cores with nanocrystalline regions of graphitic structure. They show unique properties such as high aqueous solubility, robust chemical inertness, and...

The five-layered (m = 5) Bi6Ti2.99Fe1.46Mn0.55O18 Aurivillius material is a rare example of a single-phase room temperature ferroelectric–ferrimagnetic multiferroic that shows promise for energy-efficient memory devices. Its ferrimagnetism is thought to derive from the natural partitioning of magnetic ions to the central perovskite layer, engendered by chemically driven lattice strains, together with ferromagnetic coupling via super-exchange mechanisms. Motivated by the expectation of an enhancement in magnetization with increased magnetic ion content, this study examines systematic B-site substitutions with the aim of increasing (from the current level of 40%) the proportion of magnetic ions within the structure. The solubility limits of magnetic cations in this structure and their influence on the superlattice layering are investigated. The studies of Aurivillius phase films on c-sapphire with composition Bi6TixFeyMnzO18 (B6TFMO; x = 2.3–3.2, y = 1.2–2.0, z = 0.3–0.9) demonstrated that above ∼46% of B-site magnetic cations, the m = 5 structure first rearranges into a mixed-phase material based on m = 5 and six-layered (m = 6) structures and eventually evolves into an m = 6 phase with 54% magnetic cations at the B-site. It is demonstrated that higher-layered Aurivillius homologs can be synthesized using aliovalent substitution, without requiring epitaxial growth or kinetically constrained methods. It is postulated that increasing the number of perovskite layers by forming the m = 6 structure facilitates the accommodation of additional magnetic cations at a lower average manganese oxidation state (+3.3) compared with an equivalent m = 5 stoichiometry (+4.0). While the minor out-of-plane ferroelectric response decreases as expected with increasing structural reorganization toward the m = 6 phase, the predominant in-plane piezoresponse remains unaffected by increased magnetic cation substitution. This work implies possibilities for enhanced magnetic properties in room temperature multiferroic materials, initiating the development of technologically viable ultralow-power multiferroic memory devices.

This work explores three different fabrication methods to improve light extraction efficiency of site-controlled pyramidal GaAs quantum dot (QD) system. In the theoretically analyzed structures (mimicking the as-obtained experimentally), we focus on the effects of geometry on light emission intensity, far-field profiles, and Purcell enhancement. The three methods include a back-etched approach, which exposes the pyramid’s apex, a pillar fabrication process, and a ‘mirrored’ pyramid technique. Simulation results suggest that all three techniques have the potential to improve light extraction from as grown structures, with the pillar method offering the highest extraction efficiency (43% for a numerical aperture of 0.999) and the back-etched configuration exhibiting a strong Purcell enhancement effect. The mirrored pyramid method is also of interest, as it provides a promising alternative to the back-etched approach, potentially simplifying the integration of electrical contacts for tuning QD properties. Ultimately, we emphasize the importance of precise control over the fabrication process to optimize the performance of this QD system for future applications in quantum information processing.

Flexible, microneedle-based electrodes offer an innovative solution for high-quality physiological signal monitoring, reducing the need for complex algorithms and hardware, thus streamlining health assessments, and enabling earlier disease detection. These electrodes are particularly promising for improving patient outcomes by providing more accurate, reliable, and long-term electrophysiological data, but their clinical adoption is hindered by the limited availability of large-scale population testing. This review examines the key advantages of flexible microneedle electrodes, including their ability to conform to the skin, enhance skin-electrode contact, reduce discomfort, and deliver superior signal fidelity. The mechanical and electrical properties of these electrodes are thoroughly explored, focusing on critical aspects like fracture force, skin penetration efficiency, and impedance measurements. Their applications in capturing electrophysiological signals such as ECG, EMG, and EEG are also highlighted, demonstrating their potential in clinical scenarios. Finally, the review outlines future research directions, emphasizing the importance of further studies to enhance the clinical and consumer use of flexible microneedle electrodes in medical diagnostics.

Work-related musculoskeletal disorders (WMSDs) are commonplace in industry and a host of qualitative and quantitative approaches have been used to assuage the problem, including wearable sensors and biomechanical endurance models, both of which were used in the present study. Six endurance models (consumed endurance, new improved consumed endurance and the exponential and power Frey Law and Avin general and shoulder models) with four alternative maximum torque () quantification methods, including a novel approach to generate , were compared. The proposed approach to quantify , in combination with the new improved consumed endurance model produced the lowest root mean square errors (RMSE), and indicated improved performance compared to the literature. The mean RMSE was reduced from 41.08s to 19.11s for all subjects, from 26.13s to 12.16s for males, and 51.28s to 24.45s for females using the proposed method. R 2 for 25% and 45% standardised intensity dynamic tasks were .459 and .314 respectively, P < .01. This research provided an optimised and individualised endurance prediction approach for loaded dynamic movements which can be applied to industry tasks and may lead to reduced upper-limb strains, and potentially WMSDs. List of Abbreviations ET Endurance time MVC Maximum voluntary contraction Maximum force Maximum torque SI Standardised intensity, S25 Static task at 25% SI S45 Static task at 45% SI D25 Dynamic task at 25% SI D45 Dynamic task at 45% SI , calculated using measured shoulder MVC for calculated using measured elbow MVC for calculated using gender-based MVC values for calculated using the calibration task

We present a detailed study of dual sacrificial layer structures comprising lattice-matched AlInAs and InGaAs for the efficient release of InP-based materials. The study aims to optimize surface smoothness and etch rate for transfer printing via direct bonding. This layer, combined with appropriate thicknesses, yields an extremely smooth coupon surface after release. At room temperature, we demonstrate an isotropic etch profile along with high selectivity to InP. The thickness of the release layers and dilution of the FeCl3 mixture were optimized. We show that FeCl3 and water (1:5) undercut a combined 400 nm InGaAs - 100 nm AlInAs release structure with 50% higher selectivity to InP compared with a 1:2 dilution. Such fast release with a smooth interface at room temperature yields an energy-efficient, cost-effective, and time-saving process contributing to superior printing.

In recent years, computational approaches which couple density functional theory (DFT)-based description of the electron–phonon and phonon–phonon scattering rates with the Boltzmann transport equation have been shown to obtain the electron and thermal transport characteristics of many 3D and 2D semiconductors in excellent agreement with experimental measurements. At the same time, progress in the DFT-based description of the electron–phonon scattering has also allowed to describe the non-equilibrium relaxation dynamics of hot or photo-excited electrons in several materials, in very good agreement with time-resolved spectroscopy experiments. In the latter case, as the time-resolved spectroscopy techniques provide the possibility to monitor transient material characteristics evolving on the femtosecond and attosecond time scales, the time evolution of photo-excited, nonthermal carrier distributions has to be described. Similarly, reliable theoretical approaches are needed to describe the transient transport properties of devices involving high energy carriers. In this review, we aim to discuss recent progress in coupling the ab initio description of materials, especially that of the electron–phonon scattering, with the time-dependent approaches describing the time evolution of the out-of-equilibrium carrier distributions, in the context of time-resolved spectroscopy experiments as well as in the context of transport simulations. We point out the computational limitations common to all numerical approaches, which describe time propagation of strongly out-of-equilibrium carrier distributions in 3D materials, and discuss the methods used to overcome them.

To test the validity of the quantum superposition principle at unprecedented macroscopic scales, near-field matter-wave interferometry of free-falling massive 100nm silica nanospheres from an optically cooled laser trap has been proposed [Nat. Commun. 5, 4788 (2014)10.1038/ncomms5788]. This could be realized with available technology, providing the emerging technical challenge of in-vacuum dry loading the optical trap with single 100nm silica particles, in a deterministic, repetitive, and clean manner, is addressed. Here, for the first time to our knowledge, we demonstrate, both theoretically and experimentally, a 3×3 array of custom micro-electro-mechanical system (MEMS) storage and release devices for this objective. The fabricated MEMS devices are square ultrasonic flexural silicon membranes, 400μm in side length and 8μm in thickness, monolithically integrated with a 1μm thick aluminium nitride piezoelectric transducer. The ability of the MEMS array to launch 9.98μm, 4.23μm, and 900nm silica particles in vacuum was tested experimentally using our recently developed GRIN lens-based digital holographic 3D imaging system integrated into a vacuum chamber. The minimum particle size released from the current devices is ∼4μm in diameter with the average lateral release speed in the range of 3-35 cm/s. The experimental results obtained are in good agreement with the theoretical predictions.

In this paper, we examine the effects of subband quantization on the efficacy of an L-shaped gate vertical dopingless tunneling field-effect transistor. The proposed architecture leverages an intrinsic tunneling interface that is fully aligned with the gate metal, resulting in enhanced electrostatic control. We utilized a two-step numerical simulation approach grounded in the Schrödinger-Poisson equations to evaluate the performance of our proposed device and accurately calculate the ON-state current. Additionally, we assessed the influence of defects at the heterojunction on the performance of our device. Under quantum mechanical assumptions, parameters such as ION = 23.8 µA/µm, SSAVG = 12.03 mV/dec, and the ION/IOFF ratio = 4.88 × 10¹⁰ indicate that our structure is a promising candidate for high-performance applications.

Upconversion luminescent nanomaterials have gained popularity recently due to their multitude of features that are attractive to a wide range of applications in the biomedical field. Unfortunately, their low quantum-yield (QY) has been a limiting factor. While attempts have been made to enhance their luminescence throughput over the past years, these solutions have been sub-optimal, particularly, for in vivo applications. Here, we investigate how a simple pulsed-excitation scheme can affect an enhancement in the upconversion luminescence QY up to several orders of magnitude using prudently selected pulse-widths. We perform numerical simulations using NaYF4:Yb,Tm as an example to illustrate the benefits of our proposed technique, and to derive experimental conditions for optimal QY enhancement.

Electrochemical biosensors have been extensively researched and employed across diverse fields from environmental monitoring to clinical diagnostics. Detecting biomarkers like saliva pH and glucose are crucial indicators of the health and well-being of animals and opens the door for development of new non-invasive calf health measurements. Herein, we introduce a highly sensitive and stable electrochemical sensor for detection of pH and glucose in artificial and calf saliva. Pristine gold electrodes were employed for pH measurement using the voltage where the minimum of the gold oxide reduction peak occurred as a pH indicator. For glucose sensing, we utilized an effective in-situ pH control method enabled by interdigitated microelectrodes (IDEs) to optimize pH for accurate detection of glucose in artificial and calf saliva. Glucose oxidase (GOx) was first immobilized onto a platinum black modified gold IDE array through an electrodeposition process, which involved a mixture of o- phenylenediamine (o-PD) and β-cyclodextrin (β-CD). The enzymatic based glucose sensor showed an exceptional sensitivity of −0.46 nA/mM in artificial saliva at a wide range of concentrations from 0.02 mM to 7 mM, with a LOD of 0.3 μM. Simultaneously, a sensitivity of −166 mV/pH was recorded for the pH sensor within the pH range of 5–9. These multiplexed sensors successfully detected glucose and pH levels in calf saliva noninvasively, which is particularly significant for meeting the frequent and continuous monitoring requirements of biomarkers (glucose, pH) associated with Bovine respiratory disease (BRD) and diarrhoetic calves.

Inspired by the properties of natural chitin, the present work provides the first solid foundation for growing conformal ultrathin antibacterial films of organic chitin through a solvent-free molecular layer deposition (MLD) process. This work establishes the initial groundwork for growing biomimetic hybrid cuticles by combining sugar-type molecules with vapor-phase metal−organic precursors, which we term metallochitins or, more generally, metallosaccharides. The MLD process, featuring mild temperatures and solvent-free conditions, provides exceptional conformality and thickness precision, ensuring highly conformal coatings on diverse high aspect ratio substrates. In vitro testing confirmed that the MLD-grown metallochitins not only promote the growth of various cell lines but also prevent adhesion of both Gram-negative and Gram-positive bacteria. The choice of the metal in the hybrid enables selective antimicrobial activity against Gram-negative bacteria or comprehensive antibacterial effects, which can be controlled as desired.

Significance The spatial distribution of the photosensitizing drug concentration is an important parameter for predicting the photodynamic therapy (PDT) outcome. Current diffuse fluorescence tomography methods lack accuracy in quantifying drug concentration. The development of accurate methods for monitoring the temporal evolution of the drug distribution in tissue can advance the real-time light dosimetry in PDT of tumors, leading to better treatment outcomes. Aim We develop diffuse optical tomography methods based on interstitial fluorescence measurements to accurately reconstruct the spatial distribution of fluorescent photosensitizing drugs in real-time. Approach A two-stage reconstruction algorithm is proposed. The capabilities and limitations of this method are studied in various simulated scenarios. For the first time, experimental validation is conducted using the clinical system for interstitial PDT of prostate cancer on prostate tissue-mimicking phantoms with the photosensitizer verteporfin. Results The average relative error of the reconstructed fluorophore absorption was less than 10%, whereas the fluorescent inclusion reconstructed volume relative error was less than 35%. Conclusions The proposed method can be used to monitor the temporal evolution of the photosensitizing drug concentration in tumor tissue during photodynamic therapy. This is an important step forward in the development of the next generation of real-time light dosimetry algorithms for photodynamic therapy.

First principles simulations show that copper nanoclusters preferentially take 3D adsorption structures on tungsten transition metal dichalcogenides, driven by strong copper–copper interactions.

This study aims to develop and validate a novel fast-detection electrochemical sensing platform to enhance portable electrochemical sensor solutions. The research focuses on optimising analogue front-end circuits, developing data analysis algorithms, and validating the device through experiments to enhance measurement accuracy and detection speed, enabling on-site measurements across diverse applications. This work successfully designed a Portable Unit for Lab-on-Site Electrochemistry (PULSE) system with dimensions of (78×100×2) mm3. The device’s implementation was complemented by robust firmware that performed desired electrochemical measurements, including open circuit potentiometry (OCP), chronoamperometry (CA), and cyclic voltammetry (CV). To assess its reliability, the PULSE was benchmarked against a well-established benchtop potentiostat. The results obtained highlight the system’s rapid sensing capabilities, achieving pH detection in 2 s and performing CA in 20 s. The pH calibration curve exhibited Nernstian behaviour with an accuracy of 97.58%. A correlation analysis comparing the calibration curve datasets across all electrochemical techniques from both systems revealed high correlation coefficients (>0.99), confirming the strong agreement between the two systems.

Block copolymer (BCP) patterning is a well-established self-assembly technique for developing surfaces with regular and controllable nanosized features. This method relies on the microphase separation of a BCP film and subsequent infiltration with inorganic species. The BCP film serves as a template, leaving behind inorganic replicas when removed. BCP patterning offers a promising, cost-effective alternative to standard nanopatterning techniques, featuring fewer processing steps and reduced energy use. However, BCP patterning can be complex and challenging to control. Varying the structural characteristics of the polymeric template (feature sizes) requires careful and often challenging synthesis of bespoke BCPs with controllable molecular weights (Mw). To develop BCP patterning as a standard nanofabrication approach, a vapor-phase patterning (VPP) technology has been developed. VPP allows for the simultaneous, single-step, selective swelling of BCP nanodomains to precise feature sizes and morphologies while forming inorganic features by metallic precursor infiltration. Infiltration preserves the swollen arrangement, thus allowing for feature size selection without synthesizing BCPs with different Mw, simplifying the process. VPP has the potential to revolutionize nanopatterning techniques in industries such as optical materials, materials for energy storage, sensors, and semiconductors by providing a pathway to efficient, precise, and cost-effective BCP template patterning.

A three-sectioned, bidirectionally coupled, tunable, optical comb source is presented. The photonic integrated circuit (PIC) consists of a gain section, a slotted mirror section and a Fabry-Perot (FP) section. Optical frequency combs (OFCs) are produced by gain switching the FP section via a high power radio frequency (RF) signal. An investigation into the effect of the RF frequency on the quality of the OFC is performed. Multimode behavior is observed with OFCs produced in multiple modes as well as the overall degradation in the quality of the combs in each mode. A minimal extension multimode rate equation model is presented that reproduces the experimental results extremely well using experimentally determined values for numerical parameters. The appearance of multimode behavior is interpreted as relating to the modified relaxation oscillation frequency of the bidirectionally coupled system.