The widespread use of disposable polypropylene-based personal protective equipment (PPE) in dentistry contributes significantly to healthcare waste. Sustainable approaches that promote responsible material use within educational clinical settings are increasingly needed to mitigate the environmental footprint of dental training. To evaluate the feasibility of a controlled, sustainability-oriented repurposing strategy for disposable SMS polypropylene surgical gowns in a university dental clinic, focusing on functional performance, user perception, and educational implications. A mixed-methods, quasi-experimental applied study was conducted between August and November 2025. Used SMS gowns underwent standardized inspection, cleaning, disinfection (0.1% sodium hypochlorite), terminal dry heat treatment (70-75 °C), and subsequent transformation into repurposed dental chair covers for use as non-critical barriers during non-aerosol-generating procedures. Functional performance was assessed via structured checklists. User perception and instrument reliability (α = 0.82) were evaluated through validated 5-point Likert-scale questionnaires administered to dental students (n = 148) and professionals (n = 25). This study does not aim to validate microbiological sterility or clinical repurposing of personal protective equipment, but rather to assess sustainability-oriented repurposing into non-critical barriers within an educational dental setting. Of 286 gowns collected, 205 (71.7%) met eligibility criteria and were successfully repurposed. The transformed materials demonstrated adequate stability, resistance to displacement, and tolerance to routine surface disinfection. High acceptance was reported across both groups (Global Index: 3.89/5), with significantly stronger institutional adoption support among professionals (80%) compared to students (66.2%). Preliminary environmental estimation further indicated that the intervention diverted approximately 12.9 kg of SMS polypropylene from disposal, corresponding to an estimated reduction of 20.5 kg CO₂-equivalent emissions. Controlled repurposing of disposable SMS gowns into non-critical barriers is feasible and represents a practical strategy to reduce clinical waste while fostering sustainability competencies in dental education. By integrating functional assessment, stakeholder acceptance, and preliminary environmental impact estimation within a real-world academic workflow, this study provides a replicable systems-integration model that supports the implementation of circular economy principles in dental education.
To compare the effects of blue light-filtering and non-blue light-filtering senofilcon A daily disposable contact lenses on color discrimination and contrast sensitivity in healthy young adults with myopia. This comparative study included 68 eyes of 34 myopic adults with best-corrected visual acuity of 0.0 logMAR. All participants were evaluated while wearing blue light-filtering and non-blue light-filtering senofilcon A daily disposable contact lenses. Color discrimination was assessed binocularly using the Farnsworth-Munsell 100 Hue test, with blue-yellow axis local error score (LES), red-green axis LES, and total error score (TES) recorded. Contrast sensitivity was evaluated monocularly using the Spaeth-Richman Contrast Sensitivity (SPARCS) test, and central, peripheral, and total SPARCS scores were compared between the two lens types. No statistically significant differences were observed between blue light-filtering and non-blue light-filtering contact lenses in blue-yellow axis LES (p = 0.130), red-green axis LES (p = 0.275), or TES (p = 0.090). Contrast sensitivity scores were significantly higher with blue light-filtering lenses than with non-blue light-filtering lenses in the central area (p = 0.009), superotemporal area (p = 0.024), inferotemporal area (p = 0.013), and in the total SPARCS score (p = 0.016). No significant differences were found in the superonasal or inferonasal areas. Blue light-filtering senofilcon A daily disposable contact lenses were associated with higher contrast sensitivity in central and selected peripheral visual field regions, without a measurable effect on color discrimination.
Electrical stimulation accelerates wound repair by modulating endogenous bioelectric signals that regulate inflammation, angiogenesis, extracellular matrix remodeling, and cellular responses within the wound microenvironment. However, clinical translation has been hindered by cumbersome devices with procedures that disrupt standard wound-care workflows, direct electrode contact with the wound bed, and/or limited stimulation output. Wearable Disposable Electrotherapy (WDE) integrates an electronics-free printed electrochemical architecture into an mm-thick patch that looks and is applied like a conventional bandage. The device is self-powered and delivers a single electrotherapy dose simply by application to the skin. Device dose-control (electrochemical performance) and efficacy were evaluated in a full-thickness excisional wound model in rats, compared with a sham device and a conventional Constant Current (CC) stimulator. WDE or control treatments were applied daily from day 1 through day 13, with endpoint evaluation on day 14. WDE delivered electrical stimulation comparable to CC while reducing the time required to achieve 50% wound closure by 2.08 days (~29%) relative to sham treatment. Histological and immunofluorescence analyses at day 14 demonstrated enhanced tissue remodeling, including increased collagen deposition (~25%), tissue cellularity (~73%), myofibroblast-associated αSMA expression (~2.6-fold), angiogenesis-associated CD31 expression (~2.0-fold), and increased expression of both M2- (CD206, ~2.0-fold) and M1-associated (iNOS, ~1.7-fold) markers compared with sham. A novel cellular-resolution dosimetry model, leveraging charge-based boundary element method accelerated with the fast multipole method (BEM-FMM), provides a biophysical framework linking electrical stimulation with wound microenvironment and tissue repair mechanisms. Together, these findings establish WDE as a practical bioelectric wound dressing that accelerates wound healing and tissue remodeling, with the simplicity and scalability of disposable bandages.
As robotic platform adoption expands, differences in procedural cost for inguinal hernia repair are frequently attributed to surgical technology. However, the relative contribution of surgical approach versus surgeon-specific practice patterns to cost variation remains incompletely defined. We conducted a retrospective cohort study of adults undergoing inguinal hernia repair within a multi-hospital healthcare system from 2017 to 2025. Mixed-effects regression models evaluated direct disposable supply cost and operating room time, adjusting for patient characteristics, case complexity, surgeon experience, calendar year, and clustering at both surgeon and hospital levels. The cohort included 14,313 repairs performed by 137 surgeons across 29 hospitals (open 43.8%, robotic 46.7%, laparoscopic 9.5%). Robotic utilization increased from 8.7 to 66.0% by 2024, largely replacing laparoscopy; 62% of surgeons performed only one approach. After adjustment, mean direct disposable supply cost was $567 for open, $1,527 for robotic, and $1,741 for laparoscopic repair (robot vs. laparoscopic: - $213, 95% CI - $274 to - $153, p < 0.001). Adjusted mean operating room time was 119 min for open, 142 for robotic, and 120 for laparoscopic repair (robotic vs. open: + 23.1 min, p < 0.001). Robotic repair was associated with lower odds of overnight admission (OR 0.73, 95% CI 0.55-0.96, p = 0.022). Within each platform, surgeon-level cost deviations ranged up to $777 (open) and $196 (robotic) above the platform mean, often exceeding between-platform differences. Standardized per 1,000 cases, combined potentially avoidable cost (supplies plus operating room time at $75/min) was $638,000 for robotic repairs. Surgeon-level practice variation is a major contributor to procedural cost variation in inguinal hernia repair and may provide an important target for value-improvement efforts. Because most surgeons in this cohort performed only one approach, such efforts are likely to have the greatest practical impact when directed at preference-card standardization and peer benchmarking within the platforms where surgeons already practice.
The decentralization of biosensing to point-of-need (PON) settings necessitates single-use devices that combine laboratory-level sensitivity with field-deployable simplicity. Existing fluorescent optofluidic chips achieve high sensitivity but rely on bench-top optics, pumps, and trained personnel. Here, we present a smart, disposable evanescent wave fluorescent optofluidic bio-nanochip (DEFOB) that bridges this performance gap. The DEFOB integrates a gravity-driven, 3D-printed microfluidic chip with a functionalized tapered fiber nanosensor, a compact alignment-free all-fiber optical reader, and a smartphone application. This synergistic design enables ultrasensitive, quantitative detection in both homogeneous and heterogeneous assay formats without the need for external pumps or complex peripherals. We demonstrate the platform's versatility through the laboratory-comparable quantification of sulfamerazine antibiotics via immunoassay and of SARS-CoV-2 via an integrated RAA-CRISPR/Cas12b assay, achieving detection limits of 0.06 µg/L and 0.70 copies/µL, respectively. By combining dual-mode operation, high sensitivity, quantitative accuracy, intelligence, plug-and-play functionality, and a low-cost workflow, the DEFOB platform represents a paradigm shift in PON testing, with broad applications in clinical diagnostics, environmental monitoring, and global health security.
The Alisklamp® Nero M is a novel metallic disposable circumcision device allowing thermocautery-assisted excision, immediate device removal, and standardized mucosal cuff length. This study evaluated its real-world safety profile and complication rates in a large pediatric cohort. This retrospective study included 6000 boys aged 1 month to 12 years circumcised using the Alisklamp® Nero M between November 2020 and November 2025. Procedures were performed by a single experienced surgeon using a standardized local anesthesia technique. Postoperative follow-up was conducted through a structured smartphone-based telemedicine protocol until complete wound healing. Primary and secondary outcomes were overall complication and revision surgery rates, respectively. The mean patient age was 3.14 ± 3.13 years. No patients were lost to follow-up. A total of 130 complications (2.16%) occurred, predominantly wound dehiscence (0.95%) and postoperative bleeding (0.58%). Revision surgery was required in only 10 patients (0.16%) due to persistent bleeding (n = 5) or secondary phimosis (n = 5). Remaining complications were managed conservatively, yielding complete mucocutaneous healing in all patients. Circumcision with the Alisklamp® Nero M demonstrated low overall complication and exceptionally low revision surgery rates. Standardized excision, immediate device removal, and structured telemedicine follow-up support its safety, feasibility, and practicality in routine pediatric care.
A disposable glove-derived flexible biosensor employs vertex-selective Pd-Pt nanodendrites catalyzing dissolved oxygen-mediated electrochemiluminescence, quenched by organophosphorus poisoning for on-site detection.
Prolonged digital device use can result in digital eye strain which may be exacerbated by uncorrected astigmatism. This study explored how sustained smartphone reading impacts on visual function and symptoms when astigmatism is corrected with disposable soft toric contact lenses. 30 adult contact lens wearers (mean age 23 ± 4 years, mean astigmatism 1.12 ± 0.35 D) habitually using digital devices for ≥10 h/day were fitted with Delefilcon A daily disposable toric contact lenses for 14-days. High and low contrast near visual acuity (VA) were assessed before and after a prolonged smartphone reading task on day 1 and day 14 of lens wear. The severity of digital eye strain symptoms were reported using a 0-100 visual analogue scale following the reading task. Contact lens dry eye symptoms were assessed using the 8-item Contact Lens Dry Eye Questionnaire (CLDEQ-8). At baseline, the mean high and low contrast near VAs were - 0.08 ± 0.05 and + 0.04 ± 0.08 logMAR, respectively, which did not decline significantly following the prolonged reading task, or after 14 days of lens wear. The average reading speed was not significantly different between day 1 and day 14 of lens wear (251 ± 85 words-per-minute vs 252 ± 80 words-per-minute, p = 0.47). Digital eyestrain symptoms following the reading task (mean of all symptom scores: 13 ± 21) remained stable over the 14-days of lens wear (all p > 0.05), and > 75% of the reported symptoms were ranked as <15/100 in severity. The mean CLDEQ-8 score was 15.2 ± 8.8. The correction of astigmatism with disposable toric contact lenses provided stable functional visual performance, with minimal digital eye strain during a prolonged smartphone reading task. However, over half of participants, reported significant dryness/discomfort (CLDEQ-8, ≥12) during 2-weeks of wear, highlighting a disconnect between short-term digital task symptoms and overall daily lens comfort in participants habitually using digital devices for ≥10 h/day.
To evaluate the effect of a low-molecular weight hyaluronic acid derivative (HAD), incorporated into a multipurpose disinfecting solution (MPS), on symptoms and signs of comfort during contact lens wear. Contact lens wearers with dry eye symptoms (CLDEQ-8 ≥ 12) were enrolled across three clinical trials. Participants wore comfilcon A contact lenses and used cleadew MPS with or without HAD for eight weeks, with monthly lens replacement. The first trial compared HAD-containing MPS with habitual lens care, the second compared non-HAD MPS (containing identical excipients) with habitual care, and the third directly compared HAD and non-HAD MPS. Follow-up assessments included CLDEQ-8, tear meniscus height, non-invasive tear break-up time (NITBUT), meibomian gland morphology, lipid layer thickness (LLT), tear volume (phenol red thread test), and ocular surface health assessed by slit-lamp examination and fluorescein staining. Twenty-three participants used HAD MPS and eighteen used non-HAD MPS. In all trials using HAD-containing MPS, CLDEQ-8 scores improved significantly after eight weeks (P ≤ 0.003; mean reduction ≥7.7). No significant comfort improvement was observed with non-HAD MPS (P ≤ 0.13; mean reduction ≤3.3). These symptom improvements were generally not accompanied by significant changes in tear stability, tear volume, LLT, or ocular staining. Notably, participants previously wearing daily disposable lenses and reporting discomfort demonstrated significant improvement in CLDEQ-8 scores with HAD MPS (P < 0.008), with a trend toward normalization of symptoms. HAD-containing MPS improves contact lens comfort, including in previously symptomatic daily disposable lens wearers. This benefit may relate to improved lens surface wettability and reduced friction, warranting further investigation.
Contaminated environmental surfaces contribute to the transmission of pathogens that cause healthcare-associated infections. The present study aimed to assess the efficacy and cost implications of a chlorine-based combined detergent-disinfectant used for environmental decontamination around methicillin-resistant Staphylococcus aureus (MRSA) patients. The study was conducted over a six-month period in the inpatient wards (medical, surgical, and orthopedic) of Pamela Youde Nethersole Eastern Hospital, Hong Kong Special Administrative Region, People's Republic of China. The surrounding areas of newly diagnosed MRSA patients were divided into two equal halves and decontaminated using either the conventional two-step process (cleaning with detergent followed by disinfection with a 1000 ppm hypochlorite solution) or a new one-step method using a combined detergent-disinfectant. High-touch surfaces in the patients' immediate environment were sampled before and after decontamination to detect MRSA by culture and to measure adenosine triphosphate (ATP) levels. The number of disposable wipes used and the duration of the decontamination process were recorded for the cost analysis. Both the conventional and the new methods significantly reduced the MRSA detection rate from 68.7% to 12.7% and to 15.3%, respectively (p < 0.001), and significantly reduced the ATP failure rate from 78.2% to 2.7% and to 4.5%, respectively (p < 0.001). Compared with the conventional method, the new method saved an average of 5.9 minutes of decontamination time and 10.2 disposable wipes per patient, resulting in a substantial cost saving of over 6 million Hong Kong dollars per year according to current infection control recommendations for MRSA patients in public hospitals in Hong Kong. The one-step method using a combined detergent-disinfectant effectively decontaminated high-touch hospital surfaces in the patient environment while reducing both time and costs. Its broader implementation in local inpatient settings may enhance environmental hygiene while reducing costs.
Infrared thermography allows non-invasive, real-time assessment of ocular surface temperature and represents a promising tool in contact lens (CL) research. Information regarding the short-term thermal changes before, during and after soft CL wear remains limited. This study investigated the short-term thermal response associated with daily disposable soft CL wear, the influence of CL material, and the repeatability of a portable thermographic camera. A prospective study was conducted in 29 healthy young adults (mean age 23.5 ± 4.0 years, and 65.5% women) wearing two types of daily disposable soft CLs (stenfilcon A and omafilcon B). Ocular surface temperature was recorded at baseline, 1-min, 10-min and post-CL removal using a portable thermographic camera. Measurements were repeated one week later. Statistical analyses evaluated temperature changes following CL wear, thermal changes during the first 10 min of wear, and differences between CL materials. Repeatability was assessed using intraclass correlation coefficients (ICC) and Bland-Altman analyses. Baseline and post-CL temperatures differed significantly in both sessions (both p < 0.005). Significant thermal changes were also observed between the 1-min and 10-min time points after CL insertion (both sessions p < 0.05). No material-dependent differences were found (both sessions p ≥ 0.456). Baseline temperature showed poor repeatability (ICC = 0.043), whereas the temperature change between baseline and post-CL removal showed improved agreement (ICC = 0.438). Bland-Altman analyses confirmed wider limits of agreement for baseline measurements than for temperature change. Soft CL insertion induces significant short-term thermal changes before, during and after CL wear, independent of CL material. Although absolute baseline temperature measurements showed poor repeatability, the portable infrared thermographic camera demonstrated improved agreement for the temperature change between baseline and post-CL removal and may be a useful tool for evaluating thermal changes associated with CL wear.
To disentangle the contribution of the Covid-19 pandemic and the abolition of the Seguro Popular (SP) health protection system to changes in out-of-pocket health expenditures (OPE) in Mexico during 2020. We used national representative surveys between 2014 and 2020. We described OPE in absolute and relative terms and per disposable income. Changes in OPE were estimated using adjusted two-part models. Results were reported nationally, by health insurance and income quintile. OPE increased for all in 2020 with the largest increases for the high- and very high-income households and those with social security (30.4, 23.4 and 22.2 USD, respectively). Households with no health insurance and those with Seguro Popular/Instituto de Salud para el Bienestar had the lowest increase in OPE. However, for the lowest income households and those with no social security, OPE represented the highest proportion per disposable income as their income decreased during the Covid-19. Social safety nets, including access to health care services for the uninsured and lower income households, are crucial.
Health Technology Assessment (HTA) supports evidence-based decision-making, but integrating economic evaluation within Multi-Criteria Decision Analysis (MCDA) remains challenging in hospital-level HTA. This study developed and preliminarily applied an integrated decision-support framework combining MCDA, economic evaluation, and contextualized evidence assessment to support adoption recommendations. A pragmatic digital framework integrated MCDA with Budget Impact Analysis (BIA) and Cost-Consequence Analysis (CCA) within a rule-based decision matrix. The economic module estimated cost per patient, incremental cost, budget impact, cost-consequence outputs, and, when appropriate, a supportive soft ICER. Evidence was assessed through structured critical appraisal, Summary of Findings tables, and outcome relevance, using a GRADE-informed approach mapped onto the predefined 0-1-3-5-7-9 MCDA evidence scale. Operational robustness was assessed through Failure Mode and Effects Analysis (FMEA) and self-audit controls. In a case study comparing disposable and reusable continence care systems, the disposable option showed a lower MCDA score than the current standard (2.60 vs 4.80; ΔMCDA = -2.20) and a higher cost per patient (€1.00 vs €0.65; incremental cost €0.35). Although the 3-year budget impact was €2,634 and remained within the institutional affordability threshold, the technology was classified as dominated because it generated lower value at a higher cost. The final recommendation was not favorable for routine adoption. The framework supports transparent integration of MCDA and economic evaluation in hospital-level HTA and helps distinguish affordability from overall value. The case study suggests that technologies should not be adopted solely because their budget impact is acceptable when the value-risk profile is unfavorable. Further validation across technologies and settings is required.
Accurate lens distortion correction is important for calibration, registration, image stitching, and 3D reconstruction, especially in low-data device-specific settings where disposable or specialised cameras cannot provide large calibration datasets. We address distortion correction for cameras with highly irregular or non-stationary distortion fields, where fixed polynomial models and generic learning-based rectification methods can struggle. We propose a framework based on Deep Gaussian Processes (DGPs) to model the non-linear mapping required for undistortion. The key motivation is that conventional single-layer GPs with stationary kernels must use one global notion of smoothness, whereas DGPs can represent spatially varying behaviour through composed latent mappings while preserving per-pixel predictive uncertainty. This uncertainty can be used to identify or downweight unreliable corrected regions in downstream tasks. We evaluate the method on three real camera datasets with increasing distortion complexity. The full structured acquisitions contain 512 horizontal and 512 vertical line images per camera. These are not thousands of natural calibration images, but they yield up to 29,532, 11,311, and 31,686 detected intersection correspondences for the RPI, Theta, and Pillcam datasets, respectively. This distinction is important for cameras where acquiring many independent images is impractical. The results are assessed using qualitative rectification, uncertainty maps, normalised collinearity errors, and total training time. Polynomial calibration remains strongest for the regular radial RPI distortion, while DGP and DGP2 models show lower normalised collinearity-error distributions than the standard GP and lightweight MLP baselines on the more distorted Theta and Pillcam datasets. For the full datasets, total DGP/DGP2 training times ranged from 2383.50 s to 10092.50 s, reflecting the additional computational cost of probabilistic non-stationary modelling.
Dieticyclidine (PCDE), a dissociative anesthetic related to phencyclidine, poses significant public health challenges due to its severe psychoactive effects and the lack of rapid, field-deployable detection methods. Conventional analytical techniques, such as GC-MS and LC-MS, while accurate, are costly, time-consuming, and require specialized laboratory infrastructure. This computational study employs density functional theory (DFT), time-dependent DFT (TD-DFT), and quantum theory of atoms in molecules (QTAIM) to evaluate the adsorption and sensing performance of pristine C60, aluminum-doped (AlC59), and zinc-doped (ZnC59) fullerenes toward PCDE. Calculations were performed at three theoretical levels (B97D/6-31G(d), ωB97XD/6-31G(d), and M06-2X/LANL2DZ) and showed qualitatively consistent trends for the main adsorption and sensing descriptors. According to the results, AlC59 showed strong adsorption energy (-47.56 kcal mol-1), marked electronic-structure perturbation, and an increase in the absorption wavelength from 521 to 771 nm in the presence of PCDE, along with an extremely long recovery time, making it a candidate for further experimental evaluations as an irreversible adsorbent and disposable colorimetric/electrochemical sensor. In contrast, ZnC59 shows moderate adsorption (-19.33 kcal mol-1), a favorable recovery time (102 s), and a comparable bathochromic shift to 765 nm, positioning it as a more theoretical candidate for reversible colorimetric sensing, which warrants further experimental evaluation. NCI, ELF, and LOL analyses consistently reveal that adsorption is governed predominantly by weak van der Waals interactions, with enhanced localized attractive contributions in the doped systems. We believe that the findings of this study can serve as a valuable theoretical guide for future experimental work.
Mass spectrometry (MS) evidence shows that electronic cigarettes (e-cigs) can directly emit gas phase ions at levels orders of magnitude greater than detected from typical ambient air or smoke from the mouthpiece of a traditional tobacco cigarette (t-cig). These ions, generated upon atomization of the e-liquid into an e-cig aerosol, are presumably inhaled by e-cig users. Emissions from disposable e-cigs were sampled at atmospheric pressure directly into a mass spectrometer without a conventional ion source. All four e-cigs produced mass spectra with high ion intensities, indicating that their aerosols were ion-rich upon exiting the mouthpieces. While multiple ionization pathways may contribute, atmospheric pressure thermospray ionization (APTSI) appeared to be the dominant pathway. The e-cig self-ionization process provides a direct method of aerosol analysis by mass spectrometry (MS) and eliminates the need for precollection and conventional MS ion sources. This finding has implications for e-cig user exposure that warrant further mechanistic and toxicological study.
Comparisons between transfemoral transcatheter aortic valve implantation (TF-TAVI) and surgical aortic valve replacement (SAVR) in severe aortic stenosis have demonstrated a consistent mortality benefit, lower 1 year costs and greater quality-adjusted life years in favour of TF-TAVI. However, the differences in the environmental impact of these two interventions have not yet been sufficiently investigated. The aim of the present study was to compare the intraprocedural environmental impact of these two procedures and to identify emission hotspots in order to mitigate their environmental impact. In this prospective, observational, single-centre study, usage data were collected from 15 TF-TAVI and 15 SAVR procedures. All products, energy and water consumed during the procedures were identified and were used in a comprehensive comparative environmental life cycle assessment to quantify the intraprocedural environmental impact of these two interventions. Material use in SAVR amounted to 17.7 kg compared with 8.7 kg in TF-TAVI, consisting of 84% and 69% plastics, respectively. Electricity use in TF-TAVI was 52% less than in SAVR; in both interventions, energy consumption was dominated by the use of electronic devices. In SAVR, water consumption was 30 times higher than in TF-TAVI (5800 vs 194 L), mainly due to the heating cooling system of the cardiopulmonary bypass in SAVR. In all 10 calculated environmental impact categories, SAVR had a greater life-cycle impact. Its carbon footprint was 181.2 kg CO2-eq, compared with 68.6 kg CO2-eq per TF-TAVI. TF-TAVI outperformed SAVR in all environmental impact categories and had a carbon footprint of 38% that of SAVR. In TF-TAVI, 51% less material, 52% less energy and 97% less water were used. Despite these impressive results, there is still room for improvement in the environmental impact of TF-TAVI by using fewer disposable items, powering down idle imaging systems and introducing reusable/remanufactured valve delivery systems.
Recent developments in low-cost and customizable electronics have demonstrated the remarkable potential of graphite traces produced from ordinary pencil lines as a sustainable fabrication route for next-generation devices. This review presents a systematic study of the fabrication processes, properties, and applications of pencil-drawn graphite films for electrochemical, strain, and pressure sensors, energy storage devices, photodetectors, and wearable electronics. The intrinsic advantages of this technique include simplicity, low cost, and environmental friendliness. It enables the frictional deposition of graphite flakes directly onto porous surfaces such as paper, textiles, and wood. The resulting films exhibit good electrical conductivity, flexibility, and mechanical adhesion, without requiring high-temperature processing or toxic chemicals. The major focus is on the relationship among drawing parameters, substrate roughness, and the resulting microstructural morphology, which collectively determine device performance. Pencil-drawn electrodes have enabled self-powered wearable systems, supercapacitors, thermoelectric generators, and disposable biosensors. The potential of green electronics is further enhanced by combining renewable substrates with cellulose-based materials and recyclable carbon materials. This review concludes that pencil-on-paper technology not only democratizes device fabrication but also expands its use in educational, research, and industrial settings by offering a convenient method for prototyping and functional demonstration of electronic systems.
Measuring platelet function is important for patient stratification to judge bleeding vs. thrombotic risk and for research into antiplatelet drugs to prevent cardiovascular disease. Variability in platelet function is not fully understood, and large studies of inter-individual variation are making gradual progress using laboratory measurements, but rapid and high-performance hematological tests are also needed. We present here a novel microfluidic technology for platelet function analysis that images light scatter by platelets, using a low-cost, open-source, high-throughput and customizable darkfield imaging system called Dark-Pi. The hardware consists of a camera and a simple LED light source controlled by a Raspberry Pi, with 3D-printed parts. Using the Dark-Pi, platelet aggregation was imaged within adenosine 5'-diphosphate-loaded microcapillaries, revealing clearly visible patterns. This darkfield cellular light scatter approach was previously developed for bacterial cells, and here we adapted and optimized it for directly monitoring platelet aggregation. Capturing high-quality time-resolved images of platelets undergoing activation within microcapillaries allowed us to measure changes in light scattering in platelet-rich plasma that correspond with aggregation measured using conventional laboratory methods. This novel prototype system shows that this approach may have potential for use in large-scale studies of platelet function, combining simplicity with low-cost components and using a disposable dip-and-test microfluidic format.