Flexible and wearable sensors are at the forefront of health monitoring, particularly the surge in artificial intelligence technologies. The superiority of flexible and wearable sensors over conventional sensors, which are typically composed of metal and semiconductors with restricted stretchability, has boosted biocompatibility and superior real-time monitoring capability. More recently, the biomedical research on low-molecular-weight (LMW) proteins has become increasingly significant, offering diagnostic value but presenting challenges due to their low abundance. This review aims at the discussion on the limitations of traditional and clinical detection methods. The sensing principle of flexible and wearable sensors is concisely addressed, which serves as an overview to connect with the sustainability assessment in the subsequent sections of this review. Subsequently, a compilation of the advancements in flexible and wearable sensors focusing on various aspects of LMW proteins, including materials employed, fabrication techniques, biorecognition components, and transduction processes, is introduced. The potential of contemporary LMW protein detection techniques for substituting conventional methods can be correlated from that point onwards, and the sustainability status of current flexible and wearable sensors has been examined based on critical criteria, including biocompatibility, durability, scalability, reusability, time, energy, and technical requirements. This integrated information is essential as a framework for the future development of LWM protein sensors, identifying the research gap concerning sustainability for the commercialization of these potential sensors and offering enhanced methodology beyond traditional methods.

Luminescent metal-organic frameworks (LMOFs), a specialized subset of metal-organic frameworks (MOFs) characterized by their porous structures formed from organic bridging ligands and metal-connecting nodes, have emerged as a promising avenue in material science. In this study, we report the discovery of a novel amine-functionalized zinc-based metal-organic framework (Zn-BDC-NH2 MOF). We demonstrate the controlled growth of the Zn-BDC-NH2 MOF in various morphologies and propose a plausible formation mechanism. The resulting Zn-BDC-NH2 MOF exhibits excellent luminescent properties, including high quantum yield, prolonged photon lifetime, and tunability, positioning it as a robust candidate for advanced luminescent applications.

The scalable fabrication of high‐performance nanowire (NW) photodetectors remains a critical challenge for the integration of nanoscale optoelectronics into practical technologies. This work presents a simple, rapid, and cost‐effective method for the deterministic assembly of single germanium (Ge) NWs between electrode pairs using a modified dielectrophoresis (DEP) setup. By introducing a voltage‐divider configuration with a series resistor, the method enables self‐limiting NW alignment, eliminating the need for nanoscale electrodes or extensive pre‐optimization. Devices fabricated via this approach exhibit high responsivity—exceeding 6 × 105 A W−1 at both 700 and 1550 nm—among the highest reported for single Ge NW photodetectors. This enhanced performance is attributed to asymmetric Schottky junctions and possible optical resonances within the NWs. The method enables the rapid production of single‐NW photodetectors with tunable properties, offering a versatile platform for low‐cost optoelectronic device manufacturing and advancing the feasibility of NW‐based sensing, imaging, and communication technologies.

Type-II superlattice (T2SL) devices have the potential to be the new generation of semiconductor-based devices, however fabrication of these devices leads to surface defects that can create surface leakage channels. Passivation methods that are typically used in traditional semiconductors have proved unsuccessful. In this paper we present the initial findings of a low-temperature atmospheric pressure plasma polymerisation process capable of removing the unwanted oxide layers and depositing a thin layer of polymer to protect the surface. We examine the effect of monomer flow rate on the plasma optical emission and electrical characteristics and investigate the deposition chemistry. Finally, we demonstrate the effectiveness of the plasma treatment on T2SL devices and underpin the potential for this technique. These results were presented at the 50th IOP Plasma Physics Conference, April 2024.

Nanozyme possesses multiple advantages including low cost, high stability, easy manufacture, and versatility, which have earned interest in the application of biomedical purposes. Herein, the nitrogen-graphene quantum dot (N-GQDs) decorated mixed molybdenum oxides (MMO, MoOx, 2 < x < 3) were hydrothermally fabricated to serve as the peroxidase-like nanozymes for the ultrasensitive detection of neurofilament light chain (NfL). The kinetics parameters of nanozyme including maximum velocity (Vmax) and Michaelis-Menten half-saturation constant (Km) were examined and compared with natural horseradish peroxidase (HRP). In addition, the detection principle of MMO/N-GQD-based immunosensor was established. Results show that addition of N-GQDs can trigger the electron flow from N-GQDs to MMO, making the redox center of Mo elements more effective on electron transfer. The MMO/N-GQDs/PPL/anti-NfL immunosensor exhibits excellent analytical performance on NfL detection with both UV-visible spectrophotometer or smartphone-oriented RGB reader. A linear range of 16-1000 pg mL- 1 with a limit of detection of 2.24 pg mL- 1 and recovery of 83 - 104 % in human serum is achieved. The immunosensor can attain a selectivity coefficient of higher than 0.7 against interferences containing common ions, amino acids, cholesterol, and biomarkers in serum. Results corroborate that the greensynthesized peroxidase-like MMO/N-GQD possesses the advantages of cost-effective and high scalability, which can serve as a potential nanozyme to replace natural enzyme for the ultrasensitive and selective detection of serum NfL with superior recovery in human serum.

Engineering education can be particularly challenging when dealing with abstract or highly technical concepts such as mathematics, signals, digital electronics, electronic systems, and programming. Tutorial sessions are often ineffective as a result of poor attendance and engagement, with these effects exacerbated by large class sizes, non-homogenous student groups, and the pressures of hybrid and remote learning. Gamification of some aspects of formative assessments and tutorials using mobile and app-based quizzes has proved to be successful in improving lecture theatre dynamics, reducing distractions and enhancing student attendance and engagement. Such gamified sessions can be perceived as engaging, competitive, visually appealing, and entertaining, while providing instant feedback and empowering students to navigate their own learning. Careful gamification of problem classes for engineering topics can enable more effective self-regulation of learning through a combination of effort regulation and metacognition. This paper presents both lowand high-threshold gamification strategies adopted in a U.K. higher education setting to enhance student learning in a set of challenging undergraduate engineering courses ranging from less than 30 students to more than 180 students, and qualitatively assesses impact and student reactions. While there is much literature canvassing student opinions on gamification, extensive individual student voice tends to be missing. Therefore, one of our authors, who is a recent graduate, presents a detailed reflection on her experiences of gamification. Finally, we present some conclusions for further exploration and adoption by practitioners, considering the most effective ways to deploy the various types of gamification. These conclusions include recommendations to use app-based quiz games with anonymous participation both within and outside the classroom, gamifying either single sessions or the course as a whole, and the need to continue supplementing quiz-game learning with more traditional problems and worked solutions.

A wide range of semiconductor bio sensing techniques have been demonstrated over recent years. However, due to the use of different targets and substrate materials it is often not possible to make a direct comparison. In this work we use a common Zinc Oxide platform along with the same target protein to enable a direct comparison between a range of techniques including electrical, optical and electrooptical approaches. The results indicate that while an aptamer-FET appears to provide the most sensitive, several of the other techniques provide a dual detection capability.

The dissolution of zinc oxide is investigated using spectroscopic ellipsometry to investigate its suitability as a platform for biosensing applications. The results indicate that once the ZnO surface has been functionalised, it is suitably protected, and no significant dissolving of the ZnO occurs. The binding kinetics of the SARS-CoV-2 spike protein on aptamer-functionalised zinc oxide surfaces are subsequently investigated. Values are extracted for the refractive index and associated optical constants for both the aptamer layer used and the protein itself. It is shown that upon an initial exposure to the protein, a rapid fluctuation in the surface density is observed. After around 20 min, this effect stabilises, and a fixed increase in the surface density is observed, which itself increases as the concentration of the protein is increased. This technique and setup are demonstrated to have a limit-of-detection down to 1 nanomole (nM) and display a linear response to concentrations up to 100 nM.

In this paper, we investigate the use of dielectrophoresis to align germanium nanowire arrays to realize nanowire-based diodes and their subsequent use for bio-sensing. After establishing that dielectrophoresis is a controllable and repeatable fabrication method to create devices from germanium nanowires, we use the optimum process conditions to form a series of diodes. These are subsequently functionalized with an aptamer, which is able to bind specifically to the spike protein of SARS-Cov2 and investigated as a potential sensor. We observe a linear increase in the source to drain current as the concentration of spike protein is increased from 100 fM/L to 1 nM/L.

The outbreak of the coronavirus disease 2019 (COVID-19) in December 2019 has highlighted the need for a flexible sensing system that can quickly and accurately determine the presence of biomarkers associated with the disease. This sensing system also needs to be easily adaptable to incorporate both novel diseases as well as changes in the existing ones. Here we report the feasibility of using a simple, low-cost silicon field-effect transistor functionalised with aptamers and designed to attach to the spike protein of SARS-CoV2. It is shown that a linear response can be obtained in a concentration range of 100 fM to 10 pM. Furthermore, by using a larger range of source-drain potentials compared with other FET based sensors, it is possible to look at a wider range of device parameters to optimise the response.

A novel two-way live communication process between teacher and students in large classes has been implemented using Web 2.0 polling platforms to enhance the engagement of students in classroom activities, and to allow the teacher to respond to students’ question in real time. The research question of this study was to explore and evaluate the two-way live communication between students and teachers, and among students, and how it enhances the engagement of students. To study this research question, modules from two different disciplines (electrical engineering and electronics, and psychology) have adopted the two-way live communication process. A mixed methodology, including online surveys, focus groups, and analysis of students’ responses, was followed to analyse in-depth the impact of the method on students’ engagement and learning. The study is supported by the review of the background from the literature. The outcomes of the study are discussed and compared with previous studies from the literature.

Since the beginning of the coronavirus disease 2019 (COVID-19) in December 2019 and the current lack to date of specific drugs or vaccinations to cope with the disease, it has become apparent that the surest way of dealing with this is through early diagnosis and management. Current testing has shown to be unable to rapidly and accurately provide the results required to restrict the spread. Here we report feasibility for the use of an intrinsic silicon thin film transistor functionalised with aptamers designed to attach to the spike protein of COVID-19. It is shown that a linear response can be obtained in a concentration range of 1 pM to 1 nM.

In this paper, we present single heterojunction p-i-n GaAsSbN/GaAs solar cells grown by low-temperature liquidphase epitaxy (LPE) - this is of interest as a component of multi-junction solar cell devices. The quaternary absorber layer was characterized by low excitation power photoluminescence to give the temperature dependence of the bandgap. This conformed to the Varshni function at low temperatures to within 10 meV, indicating relatively small alloy potential fluctuations. The absorption properties and the transport of the photogenerated carriers in the heterostructures were investigated using surface photovoltage method. A power conversion efficiency of 4.15% (AM1.5, 1000 W.m(-2)) was measured for p-i-n GaAsSbN/GaAs solar cells, which is comparable to the efficiency of MOCVD grown devices of this type. This is promising for the first report of LPE grown GaAsSbN/GaAs solar cells since the current record efficiency for the cells based on these compounds grown by MBE stands just at 6%. The long-wavelength photosensitivity of the cells determined from external quantum efficiency and surface photovoltage measurements was shown to be extended to 1040 nm.

We demonstrate the operation of GaSbBi metal-semiconductor-metal photodetectors with different Bi concentration and compare performance with a reference GaSb device. A GaSbBi MSM-PDs is shown to have a 220 nm wavelength extension in cut-off wavelength, with 2.9% bismuth concentration, compared to the reference device. We also investigate the influences of electrode geometry and size on the final device performance.

Multi-junction solar cells, according to the detailed balance limit, should be able to achieve efficiencies above 50 percent. Work on new materials is necessary for improvements beyond the current state of the art. In this work, we evaluate the use of GaAsSbN, which has shown promise for multi-junction solar cells, particularly targeting the 1eV cell. Epitaxial growth of this material in this work has been achieved via liquid phase epitaxy, as it can produce high quality crystalline layers. We present our initial growth and characterization results of a GaAsSbN layer. Also presented are results showing the incorporation of this material in a solar cell.

The effectiveness of a range of alternative high- ${k}$ dielectric layers as potential passivation layers for InAs avalanche photodiodes has been investigated. The suppression of surface leakage currents is investigated by analyzing the current–voltage performance of differently sized mesa diodes passivated with each oxide layer. Three potential passivation layers, such as ZnO, Al2O3, and MgO, have been identified, all of which enables the suppression of surface leakage in smaller sized devices of a radius of $50~\mu \text{m}$ and at lower temperatures of 175 K compared to a reference SU8 device. The influence of repeated temperature cycling on these layers has also been investigated with Al2O3 passivated devices, exhibiting no change in performance after multiple cooling and heating cycles.

The influence of postgrowth thermal annealing on GaSbBi Schottky barrier diodes has been investigated. The effects of the annealing temperature and time on the material quality and electrical characteristics of the diodes have been studied. The I-V characteristics indicated a better ideality factor and less leakage current at the reverse bias, as the annealing temperature increased up to 500 °C for a duration of 30 min. X-ray diffraction and scanning transmission electron microscope measurements were performed to verify that the bismuth composition was unaffected during the annealing process. Energy dispersive x-ray analysis indicated that Sb clustering occurs at high annealing temperatures, resulting in a concomitant degradation in the electrical performance. The optimum electrical characteristics of the diode were obtained with an annealing temperature of 500 °C for 30 min, resulting in an ideality factor of 1.3 being achieved.

The recent discovery of flexible graphene monolayers has triggered extensive research interest for the development of III-V/graphene functional hybrid heterostructures. In order to fully exploit their enormous potential in device applications, it is essential to optimize epitaxial growth for the precise control of nanowire geometry and density. Herein, we present a comprehensive growth study of InAs nanowires on graphitic substrates by molecular beam epitaxy. Vertically well-aligned and thin InAs nanowires with high yield were obtained in a narrow growth temperature window of 420–450 °C within a restricted domain of growth rate and V/III flux ratio. The graphitic substrates enable high nanowire growth rates, which is favourable for cost-effective device fabrication. A relatively low density of defects was observed. We have also demonstrated InAs-NWs/graphite heterojunction devices exhibiting rectifying behaviour. Room temperature photovoltaic response with a cut-off wavelength of 3.4 μm was demonstrated. This elucidates a promising route towards the monolithic integration of InAs nanowires with graphite for flexible and functional hybrid devices.

We study acceptor-type defects in GaSb1-xBix grown by molecular beam epitaxy. The hole density of the GaSb1-xBix layers, from capacitance-voltage measurements of Schottky diodes, is higher than that of the binary alloys and increases linearly up to 10(19) cm(-3) with the Bi content. Positron annihilation spectroscopy and ab initio calculations show that both Ga vacancies and Ga antisites contribute to the hole density and that the proportion of the two acceptor-type defects vary in the layers. The modification of the band gap due to Bi incorporation as well as the growth parameters are suggested to affect the concentrations of acceptor-type defects.

We report the fabrication of InAs planar avalanche photodiodes (APDs) using Be ion implantation. The planar APDs have a low background doping of 2 × 10 14 cm -3 and large depletion widths approaching 8 μm. The thick depletion width enabled a gain of 330 to be achieved at -26 V at 200 K without inducing a significant tunneling current. No edge breakdown was observed within the APDs. The surface leakage current was found to be low with a gain normalized dark current density of 400 μAcm -2 at -20 V at 200 K.