Ultra-sensitive graphene membranes for microphone applications

Microphones exploit the motion of suspended membranes to detect sound waves. Since the microphone performance can be improved by reducing the thickness and mass of its sensing membrane, graphene-based microphones are expected to outperform state-of-the-art microelectromechanical (MEMS) microphones and allow further miniaturization of the device. Here, we present a laser vibrometry study of the acoustic response of suspended multilayer graphene membranes for microphone applications. We address performance parameters relevant for acoustic sensing, including mechanical sensitivity, limit of detection and nonlinear distortion, and discuss the trade-offs and limitations in the design of graphene microphones. We demonstrate superior mechanical sensitivities of the graphene membranes, reaching more than 2 orders of magnitude higher compliances than commercial MEMS devices, and report a limit of detection as low as 15 dBSPL, which is 10 - 15 dB lower than that featured by current MEMS microphones.Comment: 34 pages, 6 figures, 7 supplementary figure

Could YouTubeTM encourage men on prostate checks? A contemporary analysis

Objectives: To assess YouTube™ videos' quality on prostate checks, especially on the digital rectal exam (DRE), and to investigate if they can inform patients correctly and eradicate their beliefs and myths.Methods: A search using as keywords "digital rectal exam for prostate cancer" was performed on the YouTubeTM platform. We selected the first 100 videos. To assess video quality content, Patient Education Materials Assessment Tool for audio-visual content (PEMAT A/V) and Misinformation tool were used.Results: Seventy-three videos were suitable for the analyses. The median PEMAT A/V Understandability score and PEMAT A/V Actionability score were 46.2% (interquartile range [IQR]: 30.8-76.9) and 50.0% (IQR: 25.0-75.0), respectively. The medi-an PEMAT A/V Understandability and Actionability scores were 69.2% (IQR: 46.2-88.5) vs 46.2% (IQR: 30.8-61.5) (p = 0.01) and 100.0% (IQR: 87.5-100.0) vs 25.0% (IQR: 25.0-68.8)(p < 0.001), for healthcare workers vs patients, respectively. According to the Misinformation tool, the median misinforma-tion score of the overall videos was 2.2 (IQR:1.7-2.8). According to the target audience, the misinformation score was 2.8 (IQR: 2.4-3.5) vs 2.0 (IQR: 1.5-2.8) (p = 0.02), for healthcare workers vs patients, respectively. Conclusions: Currently, based on our analyses, YouTubeTM videos' quality on DRE resulted unsatisfactory according to the PEMAT A/V score and the Misinformation tool. Videos targeted to healthcare workers got higher quality scores if compared to videos targeted to patients. Therefore, YouTubeTM videos' may not be considered a reliable source of information on DRE for patients

A high aspect ratio surface micromachined accelerometer based on a SiC-CNT composite material

Abstract Silicon carbide (SiC) is recognized as an excellent material for microelectromechanical systems (MEMS), especially those operating in challenging environments, such as high temperature, high radiation, and corrosive environments. However, SiC bulk micromachining is still a challenge, which hinders the development of complex SiC MEMS. To address this problem, we present the use of a carbon nanotube (CNT) array coated with amorphous SiC (a-SiC) as an alternative composite material to enable high aspect ratio (HAR) surface micromachining. By using a prepatterned catalyst layer, a HAR CNT array can be grown as a structural template and then densified by uniformly filling the CNT bundle with LPCVD a-SiC. The electrical properties of the resulting SiC-CNT composite were characterized, and the results indicated that the electrical resistivity was dominated by the CNTs. To demonstrate the use of this composite in MEMS applications, a capacitive accelerometer was designed, fabricated, and measured. The fabrication results showed that the composite is fully compatible with the manufacturing of surface micromachining devices. The Young’s modulus of the composite was extracted from the measured spring constant, and the results show a great improvement in the mechanical properties of the CNTs after coating with a-SiC. The accelerometer was electrically characterized, and its functionality was confirmed using a mechanical shaker

Highly-sensitive wafer-scale transfer-free graphene MEMS condenser microphones

Abstract Since the performance of micro-electro-mechanical system (MEMS)-based microphones is approaching fundamental physical, design, and material limits, it has become challenging to improve them. Several works have demonstrated graphene’s suitability as a microphone diaphragm. The potential for achieving smaller, more sensitive, and scalable on-chip MEMS microphones is yet to be determined. To address large graphene sizes, graphene-polymer heterostructures have been proposed, but they compromise performance due to added polymer mass and stiffness. This work demonstrates the first wafer-scale integrated MEMS condenser microphones with diameters of 2R = 220–320 μm, thickness of 7 nm multi-layer graphene, that is suspended over a back-plate with a residual gap of 5 μm. The microphones are manufactured with MEMS compatible wafer-scale technologies without any transfer steps or polymer layers that are more prone to contaminate and wrinkle the graphene. Different designs, all electrically integrated are fabricated and characterized allowing us to study the effects of the introduction of a back-plate for capacitive read-out. The devices show high mechanical compliances C m = 0.081–1.07 μmPa−1 (10–100 × higher than the silicon reported in the state-of-the-art diaphragms) and pull-in voltages in the range of 2–9.5 V. In addition, to validate the proof of concept, we have electrically characterized the graphene microphone when subjected to sound actuation. An estimated sensitivity of S 1k H z = 24.3–321 mV Pa−1 for a V b i a s  = 1.5 V was determined, which is 1.9–25.5 × higher than of state-of-the-art microphone devices while having a ~9 × smaller area

Hybrid fabrication of multimodal intracranial implants for electrophysiology and local drug delivery.

New fabrication approaches for mechanically flexible implants hold the key to advancing the applications of neuroengineering in fundamental neuroscience and clinic. By combining the high precision of thin film microfabrication with the versatility of additive manufacturing, we demonstrate a straight-forward approach for the prototyping of intracranial implants with electrode arrays and microfluidic channels. We show that the implant can modulate neuronal activity in the hippocampus through localized drug delivery, while simultaneously recording brain activity by its electrodes. Moreover, good implant stability and minimal tissue response are seen one-week post-implantation. Our work shows the potential of hybrid fabrication combining different manufacturing techniques in neurotechnology and paves the way for a new approach to the development of multimodal implants

Immunotherapy for Urological Tumors on YouTube^TM: An Information-Quality Analysis

Background: YouTubeTM is an open-access source for mass information. Several previous studies of YouTubeTM videos showed a high rate of misinformation in the urological field. The aim of the current study was to evaluate the quality of information on immunotherapy (IMT) for urological tumors uploaded to YouTubeTM. Methods: YouTubeTM videos were searched using nine keyword combinations. The PEMAT, the DISCERN tool, and the Misinformation scale were used to assess the quality of information in YouTubeTM videos about IMT for urological tumors. Descriptive statistics and Kruskal–Wallis, Chi-square, proportion, and Pearson’s tests were performed. Results: According to the selection criteria, 156 YouTubeTM videos were suitable for the analysis and stratified according to topic (urothelial carcinoma vs. renal cell cancer vs. prostate cancer vs. general information on IMT). According to PEMAT A/V, the overall Understandability score was 40% (Inter-Quartile Range [IQR]: 20–61.5) and the overall Actionability score was 0% (IQR: 0–25). According to the DISCERN tool, the overall DISCERN score was 44 (IQR: 39–53.2), defined as “fair”. According to the Misinformation scale, we recorded the lowest median overall score for item 4 (“IMT in multimodality approach”) and item 5 (“Future perspective”). Conclusions: YouTubeTM cannot be recommended as a reliable source of information on IMT for urological malignancies. In addition, YouTubeTM videos contributed to the spread of misinformation by underestimating the role of IMT in a multimodality approach and missing the findings of published clinical trial results

The spreading information of YouTube videos on Phosphodiesterase 5 inhibitors: a worrisome picture from one of the most consulted internet source

: Several previous studies on YouTubeTM information on medical topics have already been published. The current study aimed to evaluate the quality information of YouTubeTM videos on Phosphodiesterase 5 inhibitors (PDE5-is). A systematic search on YouTube™ was conducted using 30 keyword combinations. For each keyword's combination, the first 50 videos were recorded. The quality of videos on YouTube™ was assessed with Patient Education Materials Assessment Tool for audio-visual content (PEMAT A/V), DISCERN score and a specified created Misinformation tool. According to the selection criteria, 229 YouTube™ videos were suitable for the analyses. Videos were stratified according to the five main identified topics: sildenafil [n = 98; 42.79%] vs tadalafil [n = 50; 21.83%] vs vardenafil [n = 44;19.21%] vs avanafil [n = 17; 7.42%] vs PDE5-is in general [n = 20; 8.73%]. The median overall PEMAT A/V Understandability score and Actionability score were 55% (interquartile range [IQR]: 42-75) and 0% (IQR = 0-67), respectively. Specifically, according to our stratification, YouTube Videos on avanafil reached higher values of both Understandability and Actionability (72.7% and 66.7, respectively) in contrast to other categories. According to DISCERN tool, the total overall median score was 29.5 (IQR = 18-41). According to Misinformation scale, the item 1 ('sexual stimulation') harboured an overall median score of 2 (IQR = 1-2); the item 2 ('side effects') an overall median score of 2 (IQR = 1-3); the item 3 ('treatment choices') an overall median score of 1 (IQR = 1-2); the item 4 ('contraindications') an overall median score of 2 (IQR = 1-2). YouTube™ is a fast and open-access source for mass information. The overall quality of the PDE5-is contents provided is sadly unsatisfactory. Nowadays, YouTube™ cannot be recommended as a reliable source of information on PDE5-is

Incidence and Predicting Factors of Histopathological Features at Robot-Assisted Radical Prostatectomy in the mpMRI Era: Results of a Single Tertiary Referral Center

: Background and Objectives: To describe the predictors of cribriform variant status and perineural invasion (PNI) in robot-assisted radical prostatectomy (RARP) histology. To define the rates of upgrading between biopsy specimens and final histology and their possible predictive factors in prostate cancer (PCa) patients undergoing RARP. Material and Methods: Within our institutional database, 265 PCa patients who underwent prostate biopsies and consecutive RARP at our center were enrolled (2018-2022). In the overall population, two independent multivariable logistic regression models (LRMs) predicting the presence of PNI or cribriform variant status at RARP were performed. In low- and intermediate-risk PCa patients according to D'Amico risk classification, three independent multivariable LRMs were fitted to predict upgrading. Results: Of all, 30.9% were low-risk, 18.9% were intermediate-risk and 50.2% were high-risk PCa patients. In the overall population, the rates of the cribriform variant and PNI at RARP were 55.8% and 71.1%, respectively. After multivariable LRMs predicting PNI, total tumor length in biopsy cores (>24 mm [OR: 2.37, p-value = 0.03], relative to 24 mm [OR: 2.47, p = 0.01], relative to <24 mm) were independent predicting factors. In low- and intermediate-risk PCa patients, the rate of upgrading was 74.4% and 78.0%, respectively. After multivariable LRMs predicting upgrading, PIRADS (PIRADS 3 [OR: 7.01], 4 [OR: 16.98] or 5 [OR: 20.96] relative to PIRADS 2, all p = 0.01) was an independent predicting factor. Conclusions: RARP represents a tailored and risk-adapted treatment strategy for PCa patients. The indication of RP progressively migrates to high-risk PCa after a pre-operative assessment. Specifically, the PIRADS score at mpMRI should guide the decision-making process of urologists for PCa patients

Perioperative Red Cell Line Trend following Robot-Assisted Radical Prostatectomy for Prostate Cancer

Background and Objective: Blood loss represents a long-standing concern of radical prostatectomy (RP). This study aimed to assess how red line cell values changed following robot-assisted radical prostatectomy (RARP) for prostate cancer (PCa). Materials and Methods: The blood panels of 453 consecutive PCa patients undergoing RARP at a single tertiary academic referral center, from September 2020 to April 2022, were reviewed. Data from 363 patients with the blood panel available for the following timeframe: within seven days before surgery, six hours after surgery, and the first three postoperative days, were analyzed. Specifically, hemoglobin (Hb, g/dL), red blood cells (RBCs, &times;106/&mu;L), and hematocrit (HCT, %) trends were collected. Results: Considering the Hb trend, the median values in the preoperative day, postoperative day (POD) 2, and POD 3 are 14.7 (interquartile range (IQR) = 13.9&ndash;15.4), 12.1 (IQR = 11.2&ndash;12.9), and 12.2 (IQR = 11.2&ndash;13.1), respectively. The &#8710; between preoperative day and POD 2 is 2.5 (IQR = 1.8&ndash;3.2) (p &lt; 0.001). Considering the RBCs trend, the median values in the preoperative day, POD 2, and POD 3 are 4.9 (IQR = 4.7&ndash;5.3), 4.1 (IQR = 3.8&ndash;4.4), and 4.1 (IQR = 3.8&ndash;4.5), respectively. The &#8710; between preoperative day and POD 2 is 0.9 (IQR = 0.6&ndash;1.1) (p &lt; 0.001). Considering the HCT trend, the median values in the preoperative day, POD 2, and POD 3 are 44.4 (IQR = 41.7&ndash;46.6), 36.4 (IQR = 33.8&ndash;38.9), and 36.1 (IQR = 33.5&ndash;38.7), respectively. The &#8710; between preoperative day and POD 2 is 7.8 (IQR = 5.2&ndash;10.5) (p &lt; 0.001). Conclusions: Overall, patients undergoing RARP experience a significant, but clinically limited, decline in red line cell values between the preoperative time and the second day post-surgery. These observations are important to provide physicians with knowledge of the expected postoperative course and, thus, to improve the quality of patient care