Compact broadband ( O, E, S, C, L & U bands) silicon TE-pass polarizer based on ridge waveguide adiabatic S-bends.

A compact, ultra-broadband and high-performance silicon TE-pass polarizer is proposed and demonstrated experimentally. It is based on partially-etched (ridge) waveguide adiabatic S-bends, input/output tapers and side gratings on a silicon-on-insulator (SOI) platform. A compact footprint and weak back reflections are obtained due to the bent waveguide and the tapers, respectively. An extremely high extinction ratio is achieved by scattering the undesired light in the slab section using the side gratings. The 3D FDTD simulations show a TE loss less than 0.3 dB and an extinction ratio greater than 30 dB over a 500 nm wavelength range (1200 nm to 1700 nm). Measured results show a high TM loss (> 35 dB) and a low TE insertion loss (< 1.5 dB), over a 200 nm wavelength range (1450 nm to 1650 nm). The measured TE loss is < 0.6 dB at a communication wavelength of 1550 nm. The footprint of the optimized design is 65 µm × 20 µm.

Highly transparent and conductive electrodes enabled by scalable printing-and-sintering of silver nanowires.

Silver nanowires (Ag NWs) have good promised for flexible and transparent electronics. However, It remains an open question on how to achieve large-scale printing of Ag NWs with high optical transparency, electrical conductivity, and mechanical durability for practical applications, though extensive research has been conducted for more than a decade. In this work, we propose a possible solution that integrates screen printing of Ag NWs with flash-light sintering (FLS). We demonstrate that the use of low-concentration, screen-printable Ag NW ink enables large-area and high-resolution patterning of Ag NWs. A critical advantage comes from the FLS process that allows low-temperature processing, short operational time, and high output rate-characteristics that fit the scalable manufacturing. Importantly, we show that the resultant Ag NW patterns feature low sheet resistance (1.1-9.2 Ohm sq-1), high transparency (75.2-92.6%), and thus a remarkable figure of merit comparable to state of the art. These outstanding properties of Ag NW patterns, together with the scalable fabrication method we propose, would facilitate many Ag NW-based applications, such as transparent heaters, stretchable displays, and wearable devices; here, we demonstrate the novel design of flexible and transparent radio frequency 5G antennas.

National recruitment scheme for pre-registration pharmacist training in England and Wales: a mixed method evaluation of experiences of applicant pharmacy students.

BACKGROUND: A national pre-registration pharmacist training recruitment scheme, which replaces local recruitment models, was introduced in England and Wales in 2017. The national recruitment system allows pharmacy students to apply for the 52 weeks training programmes (mandatory requirement for registration as a pharmacist), through a single application system prior to undertaking a nationally administered assessment. This study aimed to explore experiences of pharmacy students on the national recruitment scheme, particularly their views on the selection methodology, application process, and offer outcomes. METHODS: This mixed method study involved a) an online survey of all (approximate n = 2800) year 4 (final year of MPharm degree) pharmacy students in England and Wales and b) a qualitative focus group with four students. The study population was eligible to participate in the 2017/18 national recruitment scheme. Survey respondents were invited to participate in a focus group. Quantitative data were analysed using descriptive and inferential analysis. Qualitative data were analysed using the framework technique. Participation was voluntary. Ethical approval from University of Birmingham was obtained. RESULTS: A total of 307 completed surveys were returned (approximate response rate 11%). Respondents were generally satisfied with the application process and commended the fairness of the selection methodology and convenience in allowing them to apply to multiple training providers. Most survey respondents (n = 181, 72.9%) were either satisfied or highly satisfied with the training programme they were offered based on their assessment performances. Three themes and eight sub-themes obtained from the analysis of over 200 open comments data from the survey and transcript of a focus group with four participants. Results suggested the need to widen the timeframe available for applicants to shortlist their preferred employers, improve the method of programme listing in the application system, and consideration of prior achievements including academic performances and placement experiences to be included in the selection methodology. CONCLUSIONS: Experiences of pharmacy students on the national recruitment scheme suggest that respondents considered the selection methodology to be fair. Student engagement and satisfaction with the recruitment system can be maximised through improved listing of employers and widening the timescales for students to shortlist their preferred employers during application process. Inclusion of University achievements in the selection methodology will require consideration of evidence based approaches. Low response rate limits generalisation of findings.

Disposable, Paper-Based, Inkjet-Printed Humidity and H2S Gas Sensor for Passive Sensing Applications.

An inkjet-printed, fully passive sensor capable of either humidity or gas sensing is presented herein. The sensor is composed of an interdigitated electrode, a customized printable gas sensitive ink and a specialized dipole antenna for wireless sensing. The interdigitated electrode printed on a paper substrate provides the base conductivity that varies during the sensing process. Aided by the porous nature of the substrate, a change in relative humidity from 18% to 88% decreases the electrode resistance from a few Mega-ohms to the kilo-ohm range. For gas sensing, an additional copper acetate-based customized ink is printed on top of the electrode, which, upon reaction with hydrogen sulphide gas (H2S) changes, both the optical and the electrical properties of the electrode. A fast response time of 3 min is achieved at room temperature for a H2S concentration of 10 ppm at a relative humidity (RH) of 45%. The passive wireless sensing is enabled through an antenna in which the inner loop takes care of conductivity changes in the 4-5 GHz band, whereas the outer-dipole arm is used for chipless identification in the 2-3 GHz band.

Fully Screen-Printed and Gentle-to-Skin Wet ECG Electrodes with Compact Wireless Readout for Cardiac Diagnosis and Remote Monitoring.

Recent advances in electrocardiogram (ECG) diagnosis and monitoring have triggered a demand for smart and wearable ECG electrodes and readout systems. Here, we report the development of a fully screen-printed gentle-to-skin wet ECG electrode integrated with a scaled-down printed circuit board (PCB) packaged inside a 3D-printed antenna-on-package (AoP). All three components of the wet ECG electrode (i.e., silver nanowire-based conductive part, electrode gel, and adhesive gel) are screen-printed on a flexible plastic substrate and only require 265 times less metal for the conductive part and 176 times less ECG electrode gel than the standard commercial wet ECG electrodes. In addition, our electrically small AoP achieved a maximum read range of 142 m and offers a 4 times larger wireless communication range than the typical commercial chip antenna. The adult volunteers' study results indicated that our system recorded ECG data that correlated well with data from a commercial ECG system and electrodes. Furthermore, in the context of a 12-lead ECG diagnostic system, the fully printed wet ECG electrodes demonstrated a performance similar to that of commercially available wet ECG electrodes while being gentle on the skin. This was confirmed through a blind review method by two cardiology consultants and one family medicine consultant, validating the consistency of the diagnostic information obtained from both electrodes. In conclusion, these findings highlight the potential of fully screen-printed wet ECG electrodes for both monitoring and diagnostic purposes. These electrodes could serve as potential candidates for clinical practice, and the screen-printing method has the capability to facilitate industrial mass production.

Wireless Technologies in Flexible and Wearable Sensing: From Materials Design, System Integration to Applications.

Wireless and wearable sensors attract considerable interest in personalized healthcare by providing a unique approach for remote, noncontact, and continuous monitoring of various health-related signals without interference with daily life. Recent advances in wireless technologies and wearable sensors have promoted practical applications due to their significantly improved characteristics, such as reduction in size and thickness, enhancement in flexibility and stretchability, and improved conformability to the human body. Currently, most researches focus on active materials and structural designs for wearable sensors, with just a few exceptions reflecting on the technologies for wireless data transmission. This review provides a comprehensive overview of the state-of-the-art wireless technologies and related studies on empowering wearable sensors. The emerging functional nanomaterials utilized for designing unique wireless modules are highlighted, which include metals, carbons, and MXenes. Additionally, the review outlines the system-level integration of wireless modules with flexible sensors, spanning from novel design strategies for enhanced conformability to efficient transmitting data wirelessly. Furthermore, the review introduces representative applications for remote and noninvasive monitoring of physiological signals through on-skin and implantable wireless flexible sensing systems. Finally, the challenges, perspectives, and unprecedented opportunities for wireless and wearable sensors are discussed.

Has a national recruitment scheme created a positive intervention for Black, Asian or other Minority Ethnic pharmacy trainees?

OBJECTIVES: A National Recruitment Scheme (NRS) for Pharmacy trainees was introduced in England and Wales in 2017, standardising recruitment processes on behalf of employers and with the aim of reducing bias for candidates applying to training posts within the National Health Service (NHS). This research attempted to identify whether the introduction of the NRS had an impact on the recruitment of Black, Asian, or other Minority Ethnic applicants into the most sought-after posts within the Scheme (hospital posts). METHODS: An observational study was undertaken. Anonymised pharmacist trainee recruitment data between the cohort intakes of 2015-16 and 2020-21 was obtained from the pharmacy regulator the General Pharmaceutical Council and a comparison of proportional representations of ethnicities was undertaken, to ascertain whether a greater proportion of applicants from minority backgrounds attained the most sought-after posts in the NHS after the NRS was introduced. A robust generalised linear model was then used to analyse the data using binomial as the variance function and logit as a link function, where the proportion of hospital recruitment was an outcome with a two-way interaction between intervention and ethnicity after adjusting for overall proportion. KEY FINDINGS: The statistical analysis of 18 283 pharmacy trainees in total, of whom 4446 were in hospital, shows a significant overall impact of intervention, with a significant positive change in the proportions of Asian-Pakistani applicants (P-value < 0.001) and Black-African applicants (P-value < 0.001) recruited to hospital posts. CONCLUSIONS: Since the introduction of the NRS there has been a statistically significant impact on the correlation between the overall number of Black, Asian or other Minority Ethnic applicants and their proportion in hospital. That is, not only is the makeup of the hospital cohort increasingly reflecting the diversity of the overall cohort, but also a larger percentage of each ethnic cohort is attaining hospital training places.

Printed Electrodes Based on Vanadium Dioxide and Gold Nanoparticles for Asymmetric Supercapacitors.

Printed energy storage components attracted attention for being incorporated into bendable electronics. In this research, a homogeneous and stable ink based on vanadium dioxide (VO2) is hydrothermally synthesized with a non-toxic solvent. The structural and morphological properties of the synthesized material are determined to be well-crystalline monoclinic-phase nanoparticles. The charge storage mechanisms and evaluations are specified for VO2 electrodes, gold (Au) electrodes, and VO2/Au electrodes using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The VO2 electrode shows an electrical double layer and a redox reaction in the positive and negative voltage ranges with a slightly higher areal capacitance of 9 mF cm-2. The VO2/Au electrode exhibits an areal capacitance of 16 mF cm-2, which is double that of the VO2 electrode. Due to the excellent electrical conductivity of gold, the areal capacitance 18 mF cm-2 of the Au electrode is the highest among them. Based on that, Au positive electrodes and VO2 negative electrodes are used to build an asymmetric supercapacitor. The device delivers an areal energy density of 0.45 µWh cm-2 at an areal power density of 70 µW cm-2 at 1.4 V in the aqueous electrolyte of potassium hydroxide. We provide a promising electrode candidate for cost-effective, lightweight, environmentally friendly printed supercapacitors.

Wearable sensors for monitoring marine environments and their inhabitants.

Human societies depend on marine ecosystems, but their degradation continues. Toward mitigating this decline, new and more effective ways to precisely measure the status and condition of marine environments are needed alongside existing rebuilding strategies. Here, we provide an overview of how sensors and wearable technology developed for humans could be adapted to improve marine monitoring. We describe barriers that have slowed the transition of this technology from land to sea, update on the developments in sensors to advance ocean observation and advocate for more widespread use of wearables on marine organisms in the wild and in aquaculture. We propose that large-scale use of wearables could facilitate the concept of an 'internet of marine life' that might contribute to a more robust and effective observation system for the oceans and commercial aquaculture operations. These observations may aid in rationalizing strategies toward conservation and restoration of marine communities and habitats.

Rapid and up-scalable manufacturing of gigahertz nanogap diodes.

The massive deployment of fifth generation and internet of things technologies requires precise and high-throughput fabrication techniques for the mass production of radio frequency electronics. We use printable indium-gallium-zinc-oxide semiconductor in spontaneously formed self-aligned <10 nm nanogaps and flash-lamp annealing to demonstrate rapid manufacturing of nanogap Schottky diodes over arbitrary size substrates operating in 5 G frequencies. These diodes combine low junction capacitance with low turn-on voltage while exhibiting cut-off frequencies (intrinsic) of >100 GHz. Rectifier circuits constructed with these co-planar diodes can operate at ~47 GHz (extrinsic), making them the fastest large-area electronic devices demonstrated to date.

National recruitment system for pre-registration pharmacist trainees in England and Wales: context, process and outcomes.

In England and Wales, a new National Recruitment Scheme (NRS) for pre-registration pharmacists was introduced in 2017. The NRS replaced the traditional method of employer-led recruitment or the national recruitment system previously limited to some hospital training programmes. NRS uses assessment methodology involving Multiple-Mini Interviews, Situational Judgement Tests and numeracy skills in ranking and appointing candidates to their preferred training providers through a centralised procedure. This commentary will describe the background, assessment methodology, outcomes of preliminary evaluations and priority research areas for the future in the context of the NRS.

CVD-Grown Monolayer Graphene-Based Geometric Diode for THz Rectennas.

For THz rectennas, ultra-fast diodes are required. While the metal-insulator-metal (MIM) diode has been investigated in recent years, it suffers from large resistance and capacitance, as well as a low cut-off frequency. Alternatively, a geometric diode can be used, which is more suitable due to its planar structure. However, there is only one report of a THz geometric diode based on a monolayer graphene. It is based on exfoliated graphene, and thus, it is not suitable for mass production. In this work, we demonstrate chemical vapor deposition (CVD)-grown monolayer graphene based geometric diodes, which are mass-producible. The diode's performance has been studied experimentally by varying the neck widths from 250-50 nm, the latter being the smallest reported neck width for a graphene geometric diode. It was observed that by decreasing the neck widths, the diode parameters such as asymmetry, nonlinearity, zero-bias resistance, and responsivity increased within the range studied. For the 50 nm neck width diode, the asymmetry ratio was 1.40 for an applied voltage ranging from -2 V to 2 V, and the zero-bias responsivity was 0.0628 A/W. The performance of the diode was also verified through particle-in-cell Monte Carlo simulations, which showed that the simulated current-voltage characteristics were consistent with our experimental results.

Flexible and reconfigurable radio frequency electronics realized by high-throughput screen printing of vanadium dioxide switches.

Smart materials that can change their properties based on an applied stimulus are in high demand due to their suitability for reconfigurable electronics, such as tunable filters or antennas. In particular, materials that undergo a metal-insulator transition (MIT), for example, vanadium dioxide (VO2) (M), are highly attractive due to their tunable electrical and optical properties at a low transition temperature of 68 °C. Although deposition of this material on a limited scale has been demonstrated through vacuum-based fabrication methods, its scalable application for large-area and high-volume processes is still challenging. Screen printing can be a viable option because of its high-throughput fabrication process on flexible substrates. In this work, we synthesize high-purity VO2 (M) microparticles and develop a screen-printable VO2 ink, enabling the large-area and high-resolution printing of VO2 switches on various substrates. The electrical properties of screen-printed VO2 switches at the microscale are thoroughly investigated under both thermal and electrical stimuli, and the switches exhibit a low ON resistance of 1.8 ohms and an ON/OFF ratio of more than 300. The electrical performance of the printed switches does not degrade even after multiple bending cycles and for bending radii as small as 1 mm. As a proof of concept, a fully printed and mechanically flexible band-pass filter is demonstrated that utilizes these printed switches as reconfigurable elements. Based on the ON and OFF conditions of the VO2 switches, the filter can reconfigure its operating frequency from 3.95 to 3.77 GHz without any degradation in performance during bending.

An investigation into the number and nature of the urgent care consultations managed and referred by community pharmacists in South-East England.

BACKGROUND: Community pharmacies are recognised as an under-utilised, accessible resource that could support the urgent care agenda. This study aimed to provide a snapshot of the number and nature of urgent care requests presented to a sample of community pharmacies in three counties in southern England, to determine how requests are managed, whether management is appropriate, as assessed by a group of experts, and whether customers receiving the care are satisfied with pharmacists' interventions. METHODS: A representative sample of pharmacists across the region was invited to keep a log-book documenting all urgent care requests over a two-week period. Data were analysed to estimate frequency and type of requests and to compare consultations in core and non-core hours. Log-book entries were scrutinised blind by an expert panel to determine appropriateness of pharmacist's responses. Customers receiving pharmacists' interventions were surveyed to assess satisfaction. RESULTS: Seventeen pharmacies kept log-books detailing 432 urgent care consultations, equating to 13 consultations per pharmacy per week. Of these, 70% (n = 302) were dealt with by the pharmacist in-house with 30% (n = 130) resulting in referrals. Locum pharmacists were significantly more likely to refer to other NHS services than regular pharmacists. Over half the requests were for symptom management, skin problems presenting most commonly (38% of all symptoms presented). Forty-seven percent of consultations were considered to have 'averted the need for other NHS services'. Pharmacists' referral (but not assessment of urgency) was deemed appropriate by the expert panel in 90% of consultations. Ninety-five percent of customers surveyed were satisfied with the service and would use the pharmacy again. CONCLUSION: Extrapolating findings across the study population (approximately 4.4 million) suggests that community pharmacists manage over 11 500 urgent care consultations per week, with 8050 managed independently. These prevent approximately 5400 other NHS encounters, while also meeting customer expectations and expert panel endorsement.

General practice pharmacists in England: Integration, mediation and professional dynamics.

BACKGROUND: A number of key publications in recent years have advocated a more integrated vision of UK primary care involving increased multi-professional communication and understanding. This has resulted in a marked change in the roles being undertaken by pharmacists. Community pharmacists have traditionally provided a medicine supply function and treated minor ailments in addition to delivering a suite of locally commissioned services; however these functions have not necessarily been part of a programme of care involving the other clinicians associated with the patient. An integrated model of care would see much closer working between pharmacy and general practice but also with pharmacists not only working with, but in the practice, in an enhanced patient-facing role, trained as independent prescribers. This has implications for the dynamics amongst professionals in this environment. OBJECTIVES: This exploratory multiple case study attempts to explore these changing dynamics across ten GP surgeries throughout the South-East of England. METHODS: Semi-structured, in-depth interviews were conducted with one nurse, one pharmacist and one physician from each clinic, and survey data was collected from 38 patients who had appointments with a pharmacist. RESULTS: The data suggested that the pharmacists who had enhanced roles perceived some uncertainty about their professional role and identity, which resulted in instability and insecurity and that this uncertainty led to both professional and interprofessional tension with their primary care colleagues. The survey data revealed that n = 35 (92%) patients stated they were 'very satisfied' or 'satisfied' with their appointment. And n = 37 (97%) were 'very comfortable' or 'comfortable' discussing their medications with the pharmacist. In addition, 36 patients (95%) reported that they strongly agreed or agreed with the clinical recommendations made by the pharmacist. CONCLUSIONS: These findings are discussed in relation to role expansion and professional/interprofessional relations before key practical suggestions are offered.

3D Crumpled Ultrathin 1T MoS2 for Inkjet Printing of Mg-Ion Asymmetric Micro-supercapacitors.

Metallic molybdenum disulfide (MoS2), e.g., 1T phase, is touted as a highly promising material for energy storage that already displays a great capacitive performance. However, due to its tendency to aggregate and restack, it remains a formidable challenge to assemble a high-performance electrode without scrambling the intrinsic structure. Here, we report an electrohydrodynamic-assisted fabrication of 3D crumpled MoS2 (c-MoS2) and its formation of an additive-free stable ink for scalable inkjet printing. The 3D c-MoS2 powders exhibited a high concentration of metallic 1T phase and an ultrathin structure. The aggregation-resistant properties of the 3D crumpled particles endow the electrodes with open space for electrolyte ion transport. Importantly, we experimentally discovered and theoretically validated that 3D 1T c-MoS2 enables an extended electrochemical stable working potential range and enhanced capacitive performance in a bivalent magnesium-ion aqueous electrolyte. With reduced graphene oxide (rGO) as the positive electrode material, we inkjet-printed 96 rigid asymmetric micro-supercapacitors (AMSCs) on a 4-in. Si/SiO2 wafer and 100 flexible AMSCs on photo paper. These AMSCs exhibited a wide stable working voltage of 1.75 V and excellent capacitance retention of 96% over 20 000 cycles for a single device. Our work highlights the promise of 3D layered materials as well-dispersed functional materials for large-scale printed flexible energy storage devices.

Fully inkjet-printed microwave passive electronics.

Fully inkjet-printed three-dimensional (3D) objects with integrated metal provide exciting possibilities for on-demand fabrication of radio frequency electronics such as inductors, capacitors, and filters. To date, there have been several reports of printed radio frequency components metallized via the use of plating solutions, sputtering, and low-conductivity pastes. These metallization techniques require rather complex fabrication, and do not provide an easily integrated or versatile process. This work utilizes a novel silver ink cured with a low-cost infrared lamp at only 80 °C, and achieves a high conductivity of 1×107 S m-1. By inkjet printing the infrared-cured silver together with a commercial 3D inkjet ultraviolet-cured acrylic dielectric, a multilayer process is demonstrated. By using a smoothing technique, both the conductive ink and dielectric provide surface roughness values of <500 nm. A radio frequency inductor and capacitor exhibit state-of-the-art quality factors of 8 and 20, respectively, and match well with electromagnetic simulations. These components are implemented in a lumped element radio frequency filter with an impressive insertion loss of 0.8 dB at 1 GHz, proving the utility of the process for sensitive radio frequency applications.

Low Cost Inkjet Printed Smart Bandage for Wireless Monitoring of Chronic Wounds.

Chronic wounds affect millions of patients around the world and their treatment is challenging as the early signs indicating their development are subtle. In addition, a type of chronic wound, known as pressure ulcer, develops in patients with limited mobility. Infection and frequent bleeding are indicators of chronic wound development. In this article, we present an unprecedented low cost continuous wireless monitoring system, realized through inkjet printing on a standard bandage, which can send early warnings for the parameters like irregular bleeding, variations in pH levels and external pressure at wound site. In addition to the early warnings, this smart bandage concept can provide long term wound progression data to the health care providers. The smart bandage comprises a disposable part which has the inkjet printed sensors and a reusable part constituting the wireless electronics. This work is an important step towards futuristic wearable sensors for remote health care applications.

Robust Design of a Particle-Free Silver-Organo-Complex Ink with High Conductivity and Inkjet Stability for Flexible Electronics.

Currently, silver-nanoparticle-based inkjet ink is commercially available. This type of ink has several serious problems such as a complex synthesis protocol, high cost, high sintering temperatures (∼200 °C), particle aggregation, nozzle clogging, poor shelf life, and jetting instability. For the emerging field of printed electronics, these shortcomings in conductive inks are barriers for their widespread use in practical applications. Formulating particle-free silver inks has potential to solve these issues and requires careful design of the silver complexation. The ink complex must meet various requirements, such as in situ reduction, optimum viscosity, storage and jetting stability, smooth uniform sintered films, excellent adhesion, and high conductivity. This study presents a robust formulation of silver-organo-complex (SOC) ink, where complexing molecules act as reducing agents. The 17 wt % silver loaded ink was printed and sintered on a wide range of substrates with uniform surface morphology and excellent adhesion. The jetting stability was monitored for 5 months to confirm that the ink was robust and highly stable with consistent jetting performance. Radio frequency inductors, which are highly sensitive to metal quality, were demonstrated as a proof of concept on flexible PEN substrate. This is a major step toward producing high-quality electronic components with a robust inkjet printing process.

Comparison of capacitive and radio frequency resonator sensors for monitoring parallelized droplet microfluidic production.

Scaled-up production of microfluidic droplets, through the parallelization of hundreds of droplet generators, has received a lot of attention to bring novel multiphase microfluidics research to industrial applications. However, apart from droplet generation, other significant challenges relevant to this goal have never been discussed. Examples include monitoring systems, high-throughput processing of droplets and quality control procedures among others. In this paper, we present and compare capacitive and radio frequency (RF) resonator sensors as two candidates that can measure the dielectric properties of emulsions in microfluidic channels. By placing several of these sensors in a parallelization device, the stability of the droplet generation at different locations can be compared, and potential malfunctions can be detected. This strategy enables for the first time the monitoring of scaled-up microfluidic droplet production. Both sensors were prototyped and characterized using emulsions with droplets of 100-150 µm in diameter, which were generated in parallelization devices at water-in-oil volume fractions (φ) between 11.1% and 33.3%.Using these sensors, we were able to measure accurately increments as small as 2.4% in the water volume fraction of the emulsions. Although both methods rely on the dielectric properties of the emulsions, the main advantage of the RF resonator sensors is the fact that they can be designed to resonate at multiple frequencies of the broadband transmission line. Consequently with careful design, two or more sensors can be parallelized and read out by a single signal. Finally, a comparison between these sensors based on their sensitivity, readout cost and simplicity, and design flexibility is also discussed.