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1.
bioRxiv ; 2024 May 15.
Article in English | MEDLINE | ID: mdl-38798508

ABSTRACT

Liver kinase B1 (LKB1/STK11) is an important regulator of pancreatic ß-cell identity and function. Elimination of Lkb1 from the ß-cell results in improved glucose-stimulated insulin secretion and is accompanied by profound changes in gene expression, including the upregulation of several neuronal genes. The mechanisms through which LKB1 controls gene expression are, at present, poorly understood. Here, we explore the impact of ß cell- selective deletion of Lkb1 on chromatin accessibility in mouse pancreatic islets. To characterize the role of LKB1 in the regulation of gene expression at the transcriptional level, we combine these data with a map of islet active transcription start sites and histone marks. We demonstrate that LKB1 elimination from ß-cells results in widespread changes in chromatin accessibility, correlating with changes in transcript levels. Changes occurred in hundreds of promoter and enhancer regions, many of which were close to neuronal genes. We reveal that dysregulated enhancers are enriched in binding motifs for transcription factors important for ß-cell identity, such as FOXA, MAFA or RFX6 and we identify microRNAs (miRNAs) that are regulated by LKB1 at the transcriptional level. Overall, our study provides important new insights into the epigenetic mechanisms by which LKB1 regulates ß-cell identity and function.

2.
Behav Sci (Basel) ; 14(5)2024 May 10.
Article in English | MEDLINE | ID: mdl-38785890

ABSTRACT

The present study aims to validate the 40-item and the brief 17-item Washoe County School District Social-Emotional Competency Assessment (WCSD-SECA), a self-report measure of social-emotional competencies, among Chinese school-aged children residing in Hong Kong. A total of 349 children (M = 9.86 years, SD = 1.22; 45.82% girls) and their parents (77.84% mothers) completed a set of questionnaires independently. The factor structure of both versions of the WCSD-SECA was assessed via confirmatory factor analyses. Structural equation models were then conducted to examine the predictive validity of the WCSD-SECA. The findings indicated that both the 40-item and the 17-item versions of the WCSD-SECA fit the data adequately. Both versions were also associated with self-reported positive and negative affect and parent-reported internalizing problems and externalizing problems. Additionally, social-emotional competencies as measured by the 40-item version were significantly associated with parent-reported prosocial behavior, whereas those as measured by the 17-item version were associated with prosocial behavior with a marginal significance. The findings demonstrated an adequate factor structure and predictive validity of the full version and the brief version of the WCSD-SECA in assessing social-emotional competencies. Hence, they serve as a useful tool for researchers, educators, and mental health practitioners to evaluate school-aged children's social-emotional competencies in the Chinese context.

3.
Sci Rep ; 14(1): 9090, 2024 04 20.
Article in English | MEDLINE | ID: mdl-38643257

ABSTRACT

Previous research suggests that mindfulness and mind wandering are opposing constructs. However, little is known about why and how they are negatively related. Through a process-oriented approach, this cross-sectional study tested self-compassion and grit as mediators for the relation between mindfulness and mind wandering. A total of 487 self-identified meditators were recruited from the UK (241 female, 49.49%). Participants reported a mean age of 38.98 years (SD = 10.03), with an average of 2.26 h of meditation practice per week (SD = 4.47). Upon informed consent, the participants completed a self-report questionnaire that assessed the core variables under study. Path analysis indicated that mindfulness was related to self-compassion. Greater self-compassion was, in turn, related to greater grit, which was then related to lower mind wandering. Bootstrapping analysis further indicated that self-compassion and grit as mediators between mindfulness and mind wandering, above and beyond age, gender, hours of meditation, income, and education as covariates. The cross-sectional findings provided initial evidence of mediation by showing that mindfulness and mind wandering were related through self-compassion and grit.


Subject(s)
Meditation , Mindfulness , Humans , Female , Adult , Attention , Cross-Sectional Studies , Self-Compassion
4.
J Fam Psychol ; 38(1): 59-70, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38032655

ABSTRACT

Adolescence is a unique developmental period marked with significant changes and challenges. As such, maintaining optimal psychological adjustment is crucial for young people, especially during the COVID-19 pandemic when their adjustment became more challenging. Self-control is a vital ability assisting individuals to navigate difficulties and stay well-adjusted during turbulent times. While the associations between adolescent self-control and adjustment have been well-documented, parental self-control has been considered to play a more fundamental role in adolescent adjustment. However, this consideration has received scant research. Drawing on the intergenerational transmission model of self-regulation, we examined an understudied yet plausible idea that parental self-control facilitates adolescent adjustment through parents' lower levels of perceived stress/better mindful parenting and adolescents' improved self-control. A two-wave survey study, spanning 1 year apart, was conducted among 426 Chinese adolescents (Mage = 11.6 years, 53.5% boys) and their parents. Parents rated their self-control, perceived stress, and mindful parenting at T1, while adolescents rated their self-control and adjustment (i.e., psychological difficulties and life satisfaction) at T1 and T2. The results of chain mediation model showed that after controlling for demographic covariates and baseline levels of adolescent self-control and adjustment, T1 paternal self-control facilitated T2 adolescent adjustment through fathers' lower levels of perceived stress and adolescents' improved self-control. By contrast, T1 maternal self-control facilitated T2 adolescent adjustment through mothers' better mindful parenting and adolescents' improved self-control. These findings advance our understanding of how self-control is transmitted from parents to offspring and clarify the processes of how parental self-control facilitates adolescent adjustment. (PsycInfo Database Record (c) 2024 APA, all rights reserved).


Subject(s)
Adolescent Behavior , Self-Control , Male , Female , Humans , Adolescent , Child , Parenting/psychology , Emotional Adjustment , Pandemics , Adolescent Behavior/psychology , Parents/psychology , Parent-Child Relations , Mothers/psychology , Stress, Psychological/etiology
5.
Sch Psychol ; 2023 Aug 10.
Article in English | MEDLINE | ID: mdl-37561429

ABSTRACT

Guided by the social cognitive theory and job demands-resources model, we used multiple regression analyses to examine the concurrent and interactive influences of professional support and efficacy beliefs on compassion fatigue during COVID-19 among 231 school principals in California. Controlling for principals' individual- and school-level demographic factors, professional support and their district collective efficacy (but not self-efficacy) were significantly and negatively associated with compassion fatigue. The negative association between professional support and compassion fatigue was moderated by both collective and self-efficacy. Professional support had a significantly negative association with compassion fatigue only among principals with both lower collective and self-efficacy beliefs. In addition, female principals reported significantly higher compassion fatigue than their male counterparts. Principals who oversee schools with larger student populations (i.e., 500-1,000 students) reported significantly less compassion fatigue than those who lead smaller schools (i.e., less than 200 students). Findings highlighted the importance of promoting principals' efficacy beliefs and increasing professional support to address their compassion fatigue. Findings also indicated that professional support and efficacy beliefs interact with each other in a compensatory way to influence the principal's compassion fatigue concurrently. Practical implications for school psychologists' capacity to support school leaders' compassion fatigue are discussed. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

6.
Micromachines (Basel) ; 14(4)2023 Apr 01.
Article in English | MEDLINE | ID: mdl-37421043

ABSTRACT

A graphene/poly(methyl methacrylate) (PMMA) closed cavity resonator with a resonant frequency at around 160 kHz has been fabricated. A six-layer graphene structure with a 450 nm PMMA laminated layer has been dry-transferred onto the closed cavity with an air gap of 105 µm. The resonator has been actuated in an atmosphere and at room temperature by mechanical, electrostatic and electro-thermal methods. The (1,1) mode has been observed to dominate the resonance, which suggests that the graphene/PMMA membrane has been perfectly clamped and seals the closed cavity. The degree of linearity of the membrane's displacement versus the actuation signal has been determined. The resonant frequency has been observed to be tuned to around 4% by applying an AC voltage through the membrane. The strain has been estimated to be around 0.08%. This research puts forward a graphene-based sensor design for acoustic sensing.

7.
Front Psychol ; 14: 1118288, 2023.
Article in English | MEDLINE | ID: mdl-37255518

ABSTRACT

Adolescents all over the world are vulnerable in facing developmental challenges. Recent studies have evidenced that the unexpected interruptions of school learning during the COVID-19 pandemic have raised concerns about the well-being of adolescents. This present study sought to investigate the relationship between mindfulness, stress, savoring beliefs, and satisfaction of life among adolescents in Hong Kong during COVID-19. A total of 240 Hong Kong Chinese adolescents between 15 and 19 years of age (M = 15.60; SD = 0.70) from schools with different religious backgrounds completed an online survey. Findings from hierarchical linear regression indicated that statistically, mindfulness negatively predicted stress and positively predicted life satisfaction and savoring beliefs. Students with faiths did not show any significant differences in mindfulness and other variables in this study from students without faiths. In terms of implications, these findings provide positive evidence that mindfulness may be an important aspect for interventions designed to enhance life satisfaction and savoring beliefs, and reduce stress of adolescents over challenging times. Overall, this study suggests youth service providers to develop effective strategies in schools and communities for further promoting wellbeing and resilience of adolescents.

8.
Article in English | MEDLINE | ID: mdl-37107775

ABSTRACT

BACKGROUND: The purpose of this study was to investigate the longitudinal processes by which blogging-related disclosure is linked to mental health. It was hypothesized that blogging had both social and cognitive benefits, including greater perceived social support and fewer memory slips, which were then associated with better mental health. METHODS: A total of 194 emerging adults were recruited three times at approximately three months apart. Participants filled out a self-report about their blogging activities and perceived benefits, social support, memory, and mental health at each time point. RESULTS: Path analysis indicated that perceived blogging-related benefits, needs, and traits mediated the relation between frequency of blogging and social support and memory slips, respectively. Moreover, social support marginally predicted greater mental health, whereas memory slips predicted poorer mental health, after controlling for baseline mental health, age, and gender. CONCLUSIONS: This study established the longitudinal associations between blogging and its benefits that may be vital for emerging adults' mental health.


Subject(s)
Blogging , Mental Health , Adult , Humans , Social Support , Self Disclosure , Cognition
9.
Article in English | MEDLINE | ID: mdl-37107850

ABSTRACT

The links between mindfulness, savoring positive experiences, and depressive symptoms have been well established in the literature. Nevertheless, little has been done to disentangle the prospective relations among these constructs. Clarifying the longitudinal relations is crucial, as it enables researchers and practitioners to discern potential trajectories of mental health interventions. In this study, 180 emerging adults between 18 and 27 years old were recruited twice at 3 months apart to complete self-reported measures including mindfulness, savoring positive experiences, and depressive symptoms. Cross-lagged path analysis indicated that savoring the moment was predictive of mindfulness three months later, whereas depressive symptoms were predictive of both mindfulness and savoring the moment three months later, above and beyond the effects of age, gender, and family income. Additionally, mindfulness, savoring positive experiences, and depressive symptoms were significantly correlated at baseline. The present study evidenced short-term inverse effects of depressive symptoms on mindfulness and savoring the moment, as well as a positive effect of savoring the moment on mindfulness. Hence, interventions geared towards reducing symptoms of depression are likely to carry concurrent and prospective benefits for psychological functioning, namely the ability to be present in the moment and to savor.


Subject(s)
Depression , Mindfulness , Humans , Adult , Adolescent , Young Adult , Depression/epidemiology , Depression/psychology , Mental Health
10.
Fam J Alex Va ; 31(3): 432-442, 2023 Jul.
Article in English | MEDLINE | ID: mdl-38603224

ABSTRACT

The COVID-19 pandemic brought about many changes in family routines and introduced new stressors for parents. While stressors can lead to parental burnout, coparenting support may mitigate the effects of parental stress on parental burnout. The current study explored the effects of parental stress, COVID-19 stress, and coparenting support on parental burnout during the second year of the pandemic. Participants consisted of one hundred fifty-five parents in the USA (M = 39.6, SD = 7.38; female = 94.8%). Results suggested parental stress was positively associated with parental burnout while coparenting support was negatively associated with parental burnout. These findings highlight the importance of addressing parental stress and support to minimize the risk of parental burnout.

11.
BMC Psychol ; 10(1): 294, 2022 Dec 09.
Article in English | MEDLINE | ID: mdl-36494754

ABSTRACT

BACKGROUND: In the face of the coronavirus disease 2019 (COVID-19) pandemic, families with young children are bombarded with new challenges and stressors. This study examined the additive and interactive effects of parental stress and negative emotions during COVID-19 on parents' severity of depressive symptoms. METHODS: Participants were 221 Chinese families involving maritally intact mothers and fathers of preschool-aged children. DISCUSSION: Path analysis indicated that mothers' parental stress interacted with their negative emotions, such that their stress was related to their severity of depressive symptoms only when negative emotions were high. By comparison, fathers' stress and negative emotions were additively associated with their severity of depressive symptoms. Supporting the cumulative risk model, parental stress during COVID-19 and negative emotions were linked to parents' severity of depressive symptoms additively or interactively, depending on the gender of the parent. These findings inform practitioners about the relevance of parents' stress and negative emotions to their severity of depressive symptoms during the pandemic.


Subject(s)
COVID-19 , Parent-Child Relations , Child , Child, Preschool , Female , Humans , Pandemics , COVID-19/epidemiology , Mothers/psychology , Parents/psychology
12.
Mindfulness (N Y) ; 13(12): 3109-3122, 2022.
Article in English | MEDLINE | ID: mdl-36373153

ABSTRACT

Objectives: Maternal stress is associated with a myriad of maladjusted outcomes among children. To identify the role of mindful parenting between mothers' stress and child adjustment during the COVID-19 pandemic, this study tested competing hypotheses with mothers' mindful parenting as a mediator versus a moderator. Methods: A total of 172 Chinese mothers of preschool-aged children participated in this study. Participants completed a self-report measure of stress during COVID-19 and mindful parenting, as well as a mother-report measure of children's prosocial behavior, internalizing problems, and externalizing problems. Structural equation models were conducted to examine the mediation versus moderation effects of mindful parenting between mothers' stress during COVID-19 and child adjustment, after controlling for family income, children's age, sex, and adjustment at baseline. Results: Findings indicated that mindful parenting mediated the link between mothers' stress during COVID-19 and child adjustment, including internalizing problems, externalizing problems, and prosocial behavior. A test of competing hypothesis showed that mindful parenting did not moderate between mothers' stress during COVID-19 and child adjustment. Conclusions: This study revealed the mediating effects of mindful parenting between mothers' perceived stress during COVID-19 and child adjustment. The findings inform researchers and practitioners about mindful parenting as a potential mechanism between maternal stress and child adjustment during the pandemic.

13.
Mindfulness (N Y) ; 13(11): 2812-2826, 2022.
Article in English | MEDLINE | ID: mdl-36248240

ABSTRACT

Objectives: Parental self-care is extremely important in the face of stress throughout parenthood. A 21-day online mindfulness-based intervention was developed that was aimed at enhancing parental well-being. The present study evaluated this intervention by examining its initial efficacy on parents' mindfulness, parenting stress, subjective well-being, and symptoms of depression and anxiety. Methods: Participants were 273 parents (90.11% mothers) who were randomly assigned to the 21-day mindfulness-based intervention group (n = 136) or waitlist control group (n = 137). Pre-intervention assessment, immediate post-intervention assessment, and 30-day follow-up assessment were conducted to assess parents' mindfulness, parenting stress, subjective well-being, and symptoms of depression and anxiety. Results: Linear mixed models indicated that the group × time effects on subjective well-being, anxiety symptoms, and mindfulness were significant, after controlling for sex, age, education, income, habit of mindfulness practice, hours of weekly mindfulness practice, and diagnostic history of psychiatric disorder. Follow-up analyses indicated that compared to baseline, participants from the intervention group reported significantly greater subjective well-being and mindfulness, and fewer symptoms of anxiety than did those from the waitlist control group. The group × time effects on parenting stress and depressive symptoms were non-significant. Exploratory findings further suggested practicality and perceived acceptability of the intervention. Conclusions: This study showed initial efficacy of a 21-day online mindfulness-based intervention on parents' subjective well-being, anxiety symptoms, and mindfulness. The findings inform researchers and practitioners about the utility of a brief mindfulness-based intervention in promotion parental well-being. Other areas of feasibility warrant future investigation.

14.
ACS Appl Mater Interfaces ; 14(43): 49026-49034, 2022 Nov 02.
Article in English | MEDLINE | ID: mdl-36259783

ABSTRACT

This work demonstrates a mixed-dimensional piezoelectric-gated transistor in the microscale that could be used as a millinewton force sensor. The force-sensing transistor consists of 1D piezoelectric zinc oxide (ZnO) nanorods (NRs) as the gate control and multilayer tungsten diselenide (WSe2) as the transistor channel. The applied mechanical force on piezoelectric NRs can induce a drain-source current change (ΔIds) on the WSe2 channel. The different doping types of the WSe2 channel have been found to lead to different directions of ΔIds. The pressure from the calibration weight of 5 g has been observed to result in an ∼30% Ids change for ZnO NRs on the p-type doped WSe2 device and an ∼-10% Ids change for the device with an n-type doped WSe2. The outcome of this work would be useful for applications in future human-machine interfaces and smart biomedical tools.

15.
Sensors (Basel) ; 22(9)2022 May 04.
Article in English | MEDLINE | ID: mdl-35591190

ABSTRACT

This paper presents a multi-axis low-cost soft magnetic tactile sensor with a high force range for force feedback in robotic surgical systems. The proposed sensor is designed to fully decouple the output response for normal, shear and angular forces. The proposed sensor is fabricated using rapid prototyping techniques and utilizes Neodymium magnets embedded in an elastomer over Hall sensors such that their displacement produces a voltage change that can be used to calculate the applied force. The initial spacing between the magnets and the Hall sensors is optimized to achieve a large displacement range using finite element method (FEM) simulations. The experimental characterization of the proposed sensor is performed for applied force in normal, shear and 45° angular direction. The force sensitivity of the proposed sensor in normal, shear and angular directions is 16 mV/N, 30 mV/N and 81 mV/N, respectively, with minimum mechanical crosstalk. The force range for the normal, shear and angular direction is obtained as 0-20 N, 0-3.5 N and 0-1.5 N, respectively. The proposed sensor shows a perfectly linear behavior and a low hysteresis error of 8.3%, making it suitable for tactile sensing and biomedical applications. The effect of the material properties of the elastomer on force ranges and sensitivity values of the proposed sensor is also discussed.


Subject(s)
Robotic Surgical Procedures , Elastomers , Feedback , Magnetic Phenomena , Mechanical Phenomena
16.
Article in English | MEDLINE | ID: mdl-35564528

ABSTRACT

Previous research suggests that self-compassion is associated with mental health and well-being. However, little has been done to understand the role of self-compassion in the family context. Hence, the present study investigated the associations between parents' self-compassion, parent's depressive symptoms, and child adjustment. A total 189 Chinese parents (101 mothers) whose children were 2-8 years old were recruited to complete a questionnaire, including measures of parents' self-compassion, depressive symptoms, and children's prosocial behavior, internalizing problems, and externalizing problems. Findings indicated mediation effects, in that parents' depressive symptoms mediated the association between their self-compassion and child adjustment outcomes, namely children's internalizing and externalizing problems, after controlling for the effects of monthly family income, child gender, and parent gender. Competing hypothesis suggested that parents' self-compassion did not moderate between parents' depressive symptoms and child adjustment outcomes. Hence, the association between parental depressive symptoms and child adjustment was not dependent on the level of parents' self-compassion. As an implication, researchers and practitioners should be made aware of the benefits of parents' self-compassion on parents' mental health and child adjustment.


Subject(s)
Depression , Self-Compassion , Child , Child, Preschool , Depression/epidemiology , Depression/psychology , Female , Humans , Mental Health , Mothers/psychology , Parent-Child Relations , Surveys and Questionnaires
17.
Mindfulness (N Y) ; 13(6): 1490-1498, 2022.
Article in English | MEDLINE | ID: mdl-35506030

ABSTRACT

Objectives: Research shows that compassion from others and from the self may enable university students to face, overcome, and bounce back from adversity and generate a greater sense of thriving and meaning in life. However, the underlying processes are largely unknown. The present study aimed to examine the associations of compassion with psychological distress, flourishing, and meaning in life among university students and explore the mechanisms underlying these associations. Methods: A total of 536 Hong Kong university students completed questionnaires measuring their experiences of compassion from others, self-compassion, resilience, psychological distress, flourishing, and meaning in life. Results: Serial mediation analyses showed that compassion from others was associated positively with self-compassion, which was, in turn, linked to greater resilience and consequently lower levels of psychological distress and higher levels of flourishing and meaning in life. Conclusions: Our findings reveal the associations of compassion from others and self-compassion with the well-being and life meaning of university students. The findings highlight the importance of being open and receptive to love and kindness from others. The findings also point to the importance of developing a caring attitude toward oneself.

18.
Diabetes ; 71(7): 1525-1545, 2022 07 01.
Article in English | MEDLINE | ID: mdl-35476777

ABSTRACT

Impaired pancreatic ß-cell function and insulin secretion are hallmarks of type 2 diabetes. miRNAs are short, noncoding RNAs that silence gene expression vital for the development and function of ß cells. We have previously shown that ß cell-specific deletion of the important energy sensor AMP-activated protein kinase (AMPK) results in increased miR-125b-5p levels. Nevertheless, the function of this miRNA in ß cells is unclear. We hypothesized that miR-125b-5p expression is regulated by glucose and that this miRNA mediates some of the deleterious effects of hyperglycemia in ß cells. Here, we show that islet miR-125b-5p expression is upregulated by glucose in an AMPK-dependent manner and that short-term miR-125b-5p overexpression impairs glucose-stimulated insulin secretion (GSIS) in the mouse insulinoma MIN6 cells and in human islets. An unbiased, high-throughput screen in MIN6 cells identified multiple miR-125b-5p targets, including the transporter of lysosomal hydrolases M6pr and the mitochondrial fission regulator Mtfp1. Inactivation of miR-125b-5p in the human ß-cell line EndoCß-H1 shortened mitochondria and enhanced GSIS, whereas mice overexpressing miR-125b-5p selectively in ß cells (MIR125B-Tg) were hyperglycemic and glucose intolerant. MIR125B-Tg ß cells contained enlarged lysosomal structures and had reduced insulin content and secretion. Collectively, we identify miR-125b as a glucose-controlled regulator of organelle dynamics that modulates insulin secretion.


Subject(s)
Diabetes Mellitus, Type 2 , Insulin-Secreting Cells , MicroRNAs , AMP-Activated Protein Kinases/metabolism , Animals , Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/metabolism , Glucose/metabolism , Glucose/pharmacology , Humans , Insulin-Secreting Cells/metabolism , Mice , MicroRNAs/genetics , MicroRNAs/metabolism
19.
Sensors (Basel) ; 21(17)2021 Aug 31.
Article in English | MEDLINE | ID: mdl-34502762

ABSTRACT

The addition of piezoelectric zinc oxide (ZnO) fillers into a flexible polymer matrix has emerged as potential piezocomposite materials that can be used for applications such as energy harvesters and pressure sensors. A simple approach for the fabrication of PDMS-ZnO piezoelectric nanocomposites based on two ZnO fillers: nanoparticles (NP) and nanoflowers (NF) is presented in this paper. The effect of the ZnO fillers' geometry and size on the thermal, mechanical and piezoelectric properties is discussed. The sensors were fabricated in a sandwich-like structure using aluminium (Al) thin films as top and bottom electrodes. Piezocomposites at a concentration of 10% w/w showed good flexibility, generating a piezoelectric response under compression force. The NF piezocomposites showed the highest piezoelectric response compared to the NP piezocomposites due to their geometric connectivity. The piezoelectric compound NF generated 4.2 V while the NP generated 1.86 V under around 36 kPa pressure. The data also show that the generated voltage increases with increasing applied force regardless of the type of filler.

20.
ACS Appl Mater Interfaces ; 13(32): 38792-38798, 2021 Aug 18.
Article in English | MEDLINE | ID: mdl-34337933

ABSTRACT

We report the realization of an acoustic capacitive microphone formed by graphene/poly(methyl methacrylate) (PMMA). It is the first time that the ultra-large graphene/PMMA membrane suspended fully over the cavity has been fabricated by releasing the silicon dioxide sacrificial layer underneath the membrane. The novelty in the fabrication method is that the silicon dioxide layer has been etched by hydrogen fluoride vapor from the back of the partly etched silicon substrate. Using the new process, the ultra-large graphene/PMMA membrane, with a diameter to thickness ratio of 7800, has been suspended over the cavity with a 2 µm air gap. The spacing of 2 µm is the minimum gap over the graphene-based acoustic capacitive microphones which have been reported so far. The static deformation of the suspended graphene/PMMA membrane after silicon dioxide has been etched is estimated to be 270 nm. The aspect ratio of the membrane's diameter over its static deformation is around 13,000, which shows that the graphene/PMMA membrane with a diameter of a few millimeters can be transferred and suspended over the substrate with relatively small deformation by releasing the sacrificial silicon dioxide layer. The dynamic behavior of the device under electrostatic actuation has been characterized. The acoustic response of the graphene/PMMA capacitive microphone has been measured, and the sensitivity has been observed to be -47.5 dB V (4.22 mV/Pa) ± 10%. The strain in the graphene/PMMA membrane is estimated to be 0.034%.

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