1.Association of physical activity with overweight/obesity, depressive symptoms and their co-occurrence among junior and senior high school students
LU Qu, CHEN Manman, WANG Jiahui, JIANG Yu, GU Fang, DONG Bin
Chinese Journal of School Health 2026;47(3):355-359
Objective:
To analyze the associations of physical activity with overweight/obesity, depressive symptoms, and their co-occurrence among junior and senior high school students, so as to provide reference for optimizing physical activity intervention strategies and promoting healthy lifestyles.
Methods:
From March to November 2023, a cross sectional survey was conducted among 90 457 junior and senior high school students aged 11-18 years in Zhejiang Province using a stratified cluster random sampling method. Data on physical activity and dietary behavior were collected through questionnaires, height and weight were measured. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D). The Chi-square test was used to examine differences, and Logistic regression was applied to evaluate the associations of physical activity characteristics with overweight/obesity, depressive symptoms, and their co-occurrence. Additionally, the effectiveness of physical activity performed on rest days versus work days was examined.
Results:
The prevalence of overweight/obesity, depressive symptoms, and their co-occurrence among junior and senior high school students were 25.1%, 27.9%, and 6.7%, respectively, with significant sex differences ( χ 2=2 005.3, 587.7, 99.6, all P <0.01). Logistic regression analysis showed that students with insufficient physical activity had a higher risk of overweight/obesity compared with those with sufficient physical activity ( OR=1.12, 95%CI=1.06-1.17, P <0.01). Comparing to students who exercised 0-1 day per week, those who exercised 5-7 days per week were associated with a reduced risk of overweight/obesity and depressive symptoms ( OR=0.93, 95%CI =0.90-0.97; OR=0.95, 95%CI =0.91-0.99, both P <0.05). When total activity volume and frequency were held constant, students with sufficient rest day physical activity had lower risks of overweight/obesity, depressive symptoms, and their co-occurrence than those with insufficient rest day activity (all P < 0.01).
Conclusions
Sufficient amount of physical activity and higher frequency of rest day physical activity are significantly associated with lower risks of overweight/obesity, depressive symptoms, and their co-occurrence in adolescents. Physical activity performed on rest days may confer greater health benefits than activity performed on work days.
2.Impact of social capital, adverse childhood experiences and depressive symptoms on suicidal behavior among vocational high school students
YU Bin, YAN Jingyan, CHEN Xinguang, GUO Yan, LI Fang, YAN Hong, XIAO Chenchang
Chinese Journal of School Health 2026;47(4):506-511
Objective:
To explore the nonlinear dynamic effects of social capital, adverse childhood experiences (ACEs) and depressive symptoms on suicidal behavior among vocational high school students, so as to provide theoretical basis and practical references for formulating suicide prevention strategies.
Methods:
A convenience sampling method was employed to include 668 students from a vocational high school from Wuhan in March 2023. Social capital was used as the asymmetry variable, while ACEs and depressive symptoms were used as bifurcation variables, a cusp catastrophe model was constructed to analyze the nonlinear changes in suicidal behavior among vocational high school students, and its fit was compared with linear and Logistic regression models.
Results:
Among students in the health vocational high school in Wuhan, only suicidal ideation accounted for 8.5%, only suicide attempt for 18.6%, neither accounted for 31.9%, and both for 41.0%. Gender, left behind experience, family economic status, parental parenting styles, depressive symptoms, social capital, and ACEs were all related factors influencing suicidal behavior among vocational high school students ( χ 2/H=19.03, 13.33, 21.11, 46.70, 144.38, 24.61, 118.77, all P <0.05). Violin plots showed a bimodal distribution of suicidal behavior, indicating nonlinear variation characteristics. The cusp catastrophe model results showed that social capital was negatively correlated with suicidal behavior, but the relationship was bifurcated by ACEs ( α social capital = -0.006 , β ACEs =0.075) and depressive symptoms ( α social capital =-0.013, β depressive =0.028) (all P <0.05). When both ACEs and depressive symptoms coexisted, the impact of ACEs was stronger ( β ACEs =0.077, β depressive =0.014) (both P <0.05). The cusp catastrophe model fitted ( R 2=0.886, 0.881, 0.882) better than the linear ( R 2=0.258, 0.219, 0.258) and Logistic regression models ( R 2= 0.242, 0.211 , 0.176). Gender stratified analysis results showed that bifurcation effect of ACEs was stronger in males than in females( β boys =0.224, β girls =0.086); in females, both ACEs and depressive symptoms had a bifurcation effect, with the former showing a stronger effect ( β ACEs =0.062, β depressive =0.015) (all P <0.05).
Conclusions
Suicidal behavior among vocational high school students exhibits nonlinear characteristics. Improving social capital to reducing ACEs and depressive symptoms may contribute to decreasing adolescent suicidal behaviors.
3.Finite element analysis of internal fixation with new retrograde intramedullary nail on lateral femur condyle for distal type A2 femur fractures
Xinlin YU ; Huiyu CHEN ; Yingying WANG ; Weizhong GUO ; Bin FENG ; Chengshou LIN ; Wang LIN
Chinese Journal of Tissue Engineering Research 2026;30(3):546-552
BACKGROUND:Plate fixation is the mainstream method for the surgical treatment of distal femoral fractures.The intramedullary nailing has the advantages of minimally invasive,such as less soft tissue injury and bone blood supply destruction.At the same time,it is a central fixation and has better biomechanical effect.Therefore,retrograde intramedullary nailing has become another option for the internal fixation of distal femoral fractures.OBJECTIVE:The biomechanical characteristics of new retrograde intramedullary nail on lateral femur condyle,common femoral retrograde intramedullary nail,and lateral femur condyle anatomical locking plate for the treatment of A2-type distal femoral fractures were compared using finite element analysis,and the advantages of new retrograde intramedullary nail on lateral femur condyle was studied.METHODS:A new retrograde intramedullary nail on lateral femur condyle was designed,which was inserted into the bone cortex in front of the insertion point of the lateral collateral ligament of the lateral femoral condyle.A CT scan was performed on the lower limb bone of a male volunteer,and a three-dimensional model of the femur was established.The model was then segmented to create a three-dimensional model of a femoral distal A2-type fracture,The three-dimensional models of small(small group),standard type retrograde intramedullary nail on the lateral femoral condyle(standard group),common retrograde intramedullary needle(common group),and lateral femur condyle anatomical locking plate(plate group)were established respectively.The axial stresses of 600,1 800 N and the torsional load of 4 000,8 000 N·mm were applied to the models,and the displacement and stress of femur and the displacement,stress and shear force of internal fixators were observed in each group.RESULTS AND CONCLUSION:(1)When subjected to axial load of 600 and 1 800 N,the femoral peak displacement,the femoral peak stress,and the peak stress of interal fixation in the standard group were the lowest among the four groups.(2)When subjected to torsional load of 4 000 and 8 000 N·mm,the femoral peak displacement and peak displacement of the internal fixation in the standard group were the lowest among the four groups.(3)Compared with femoral lateral condylar locking plate and common retrograde intramedullary needle,the new retrograde intramedullary needle on lateral femur condyle has mechanical advantages of reducing stress concentration and decreasing the risk of internal fixation failure.
4.Finite element analysis of internal fixation with new retrograde intramedullary nail on lateral femur condyle for distal type A2 femur fractures
Xinlin YU ; Huiyu CHEN ; Yingying WANG ; Weizhong GUO ; Bin FENG ; Chengshou LIN ; Wang LIN
Chinese Journal of Tissue Engineering Research 2026;30(3):546-552
BACKGROUND:Plate fixation is the mainstream method for the surgical treatment of distal femoral fractures.The intramedullary nailing has the advantages of minimally invasive,such as less soft tissue injury and bone blood supply destruction.At the same time,it is a central fixation and has better biomechanical effect.Therefore,retrograde intramedullary nailing has become another option for the internal fixation of distal femoral fractures.OBJECTIVE:The biomechanical characteristics of new retrograde intramedullary nail on lateral femur condyle,common femoral retrograde intramedullary nail,and lateral femur condyle anatomical locking plate for the treatment of A2-type distal femoral fractures were compared using finite element analysis,and the advantages of new retrograde intramedullary nail on lateral femur condyle was studied.METHODS:A new retrograde intramedullary nail on lateral femur condyle was designed,which was inserted into the bone cortex in front of the insertion point of the lateral collateral ligament of the lateral femoral condyle.A CT scan was performed on the lower limb bone of a male volunteer,and a three-dimensional model of the femur was established.The model was then segmented to create a three-dimensional model of a femoral distal A2-type fracture,The three-dimensional models of small(small group),standard type retrograde intramedullary nail on the lateral femoral condyle(standard group),common retrograde intramedullary needle(common group),and lateral femur condyle anatomical locking plate(plate group)were established respectively.The axial stresses of 600,1 800 N and the torsional load of 4 000,8 000 N·mm were applied to the models,and the displacement and stress of femur and the displacement,stress and shear force of internal fixators were observed in each group.RESULTS AND CONCLUSION:(1)When subjected to axial load of 600 and 1 800 N,the femoral peak displacement,the femoral peak stress,and the peak stress of interal fixation in the standard group were the lowest among the four groups.(2)When subjected to torsional load of 4 000 and 8 000 N·mm,the femoral peak displacement and peak displacement of the internal fixation in the standard group were the lowest among the four groups.(3)Compared with femoral lateral condylar locking plate and common retrograde intramedullary needle,the new retrograde intramedullary needle on lateral femur condyle has mechanical advantages of reducing stress concentration and decreasing the risk of internal fixation failure.
5.Neuroprotective Effects of Transcranial Magneto-acoustic Stimulation on Parkinson’s Disease Model Mice by Regulating Mitophagy and Mitochondrial Homeostasis
Shuai ZHANG ; Yan-Bin WANG ; Yi-Hao XU ; Jin-Rui MI ; Xiao-Chao LU ; Yu-Chen AN ; Ji-Zhou LIU ; Jia-Qi SUN
Progress in Biochemistry and Biophysics 2026;53(5):1457-1470
ObjectiveTranscranial magneto-acoustic stimulation (TMAS) is an emerging non-invasive neuromodulation technique that may provide a novel non-pharmacological intervention strategy for Parkinson's disease (PD). PD is characterized by the progressive degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNc), leading to motor impairments such as bradykinesia, tremor, and rigidity. Increasing evidence indicates that mitochondrial dysfunction and impaired mitochondrial quality control are central mechanisms underlying dopaminergic neuronal loss. In particular, abnormalities in mitophagy and mitochondrial fission-fusion balance contribute substantially to oxidative stress, energy metabolic failure, and neuronal injury. At present, most clinical treatments for PD mainly alleviate symptoms but do not effectively halt disease progression. Therefore, exploring new interventions targeting the core pathological mechanisms is of considerable significance. This study aims to investigate whether TMAS can improve neural damage and motor dysfunction in PD mice by regulating mitophagy and the fission/fusion dynamic balance, thereby providing theoretical and experimental support for its application in PD treatment. MethodsMale C57BL/6 mice were used in this study. A PD model was established by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) for 7 consecutive days. After model induction, mice in the intervention group received TMAS once daily for 14 consecutive days, whereas the corresponding control group received sham stimulation. The stimulation target was positioned over the primary motor cortex (M1). Motor performance was evaluated using the pole test and the open-field test. To verify the activation effect of TMAS on the target cortical region, c-Fos immunohistochemistry was performed in the M1. To assess nigral dopaminergic neuronal injury, tyrosine hydroxylase (TH) immunohistochemistry was used to quantify TH-positive neurons in the SNc. Mitochondrial function was evaluated by measuring reactive oxygen species (ROS) levels and adenosine triphosphate (ATP) content in the SNc. Western blot was further performed to determine the expression of mitophagy-related proteins, including PINK1, Parkin, LC3-II, and p62, as well as mitochondrial dynamics-related proteins, including Drp1 and Opa1. ResultsTMAS significantly increased the number of c-Fos-positive cells in M1 (P<0.000 1), indicating effective activation of neurons in the targeted cortical region. Compared with the control group, MPTP-treated mice exhibited marked motor dysfunction, including a significant reduction in total distance traveled in the open-field test (P<0.000 1) and mean speed (P=0.000 1), as well as significant prolongation of turn time and total climbing time in the pole test (P<0.000 1). These behavioral impairments were accompanied by a substantial loss of TH-positive dopaminergic neurons in the SNc, whereas TMAS significantly increased TH-positive neuron survival (P<0.000 1). In parallel, MPTP induced a pronounced increase in ROS levels and a significant reduction in ATP content, indicating severe mitochondrial dysfunction and energy metabolism impairment (P<0.01). TMAS treatment significantly improved motor performance, as reflected by the reversal of MPTP-induced impairment in the open-field and pole tests, and significantly reduced ROS accumulation (P<0.01) while restoring ATP production (P<0.001). At the molecular level, MPTP markedly downregulated PINK1 and Parkin, decreased p62 expression, increased LC3-II accumulation, elevated Drp1 expression, and reduced Opa1 expression, whereas TMAS significantly reversed these abnormalities, suggesting restoration of mitophagy-related mitochondrial quality control and re-establishment of mitochondrial fission-fusion balance. Collectively, these findings indicate that TMAS ameliorates MPTP-induced neurotoxicity and restores mitochondrial homeostasis and energy metabolism. ConclusionTMAS effectively attenuates neural damage and improves motor dysfunction in MPTP-induced PD mice. Its neuroprotective effects are closely associated with multidimensional regulation of the mitochondrial quality control system, including restoration of PINK1/Parkin-mediated mitophagy and rebalancing of Drp1/Opa1-related mitochondrial dynamics. Rather than acting only as a symptomatic neuromodulatory intervention, TMAS may influence a key pathological axis of PD by improving mitochondrial homeostasis in SNc and protecting nigral dopaminergic neurons. These findings provide experimental evidence supporting TMAS as a promising non-invasive physical intervention for PD.
6.Neuroprotective Effects of Transcranial Magneto-acoustic Stimulation on Parkinson’s Disease Model Mice by Regulating Mitophagy and Mitochondrial Homeostasis
Shuai ZHANG ; Yan-Bin WANG ; Yi-Hao XU ; Jin-Rui MI ; Xiao-Chao LU ; Yu-Chen AN ; Ji-Zhou LIU ; Jia-Qi SUN
Progress in Biochemistry and Biophysics 2026;53(5):1457-1470
ObjectiveTranscranial magneto-acoustic stimulation (TMAS) is an emerging non-invasive neuromodulation technique that may provide a novel non-pharmacological intervention strategy for Parkinson's disease (PD). PD is characterized by the progressive degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNc), leading to motor impairments such as bradykinesia, tremor, and rigidity. Increasing evidence indicates that mitochondrial dysfunction and impaired mitochondrial quality control are central mechanisms underlying dopaminergic neuronal loss. In particular, abnormalities in mitophagy and mitochondrial fission-fusion balance contribute substantially to oxidative stress, energy metabolic failure, and neuronal injury. At present, most clinical treatments for PD mainly alleviate symptoms but do not effectively halt disease progression. Therefore, exploring new interventions targeting the core pathological mechanisms is of considerable significance. This study aims to investigate whether TMAS can improve neural damage and motor dysfunction in PD mice by regulating mitophagy and the fission/fusion dynamic balance, thereby providing theoretical and experimental support for its application in PD treatment. MethodsMale C57BL/6 mice were used in this study. A PD model was established by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) for 7 consecutive days. After model induction, mice in the intervention group received TMAS once daily for 14 consecutive days, whereas the corresponding control group received sham stimulation. The stimulation target was positioned over the primary motor cortex (M1). Motor performance was evaluated using the pole test and the open-field test. To verify the activation effect of TMAS on the target cortical region, c-Fos immunohistochemistry was performed in the M1. To assess nigral dopaminergic neuronal injury, tyrosine hydroxylase (TH) immunohistochemistry was used to quantify TH-positive neurons in the SNc. Mitochondrial function was evaluated by measuring reactive oxygen species (ROS) levels and adenosine triphosphate (ATP) content in the SNc. Western blot was further performed to determine the expression of mitophagy-related proteins, including PINK1, Parkin, LC3-II, and p62, as well as mitochondrial dynamics-related proteins, including Drp1 and Opa1. ResultsTMAS significantly increased the number of c-Fos-positive cells in M1 (P<0.000 1), indicating effective activation of neurons in the targeted cortical region. Compared with the control group, MPTP-treated mice exhibited marked motor dysfunction, including a significant reduction in total distance traveled in the open-field test (P<0.000 1) and mean speed (P=0.000 1), as well as significant prolongation of turn time and total climbing time in the pole test (P<0.000 1). These behavioral impairments were accompanied by a substantial loss of TH-positive dopaminergic neurons in the SNc, whereas TMAS significantly increased TH-positive neuron survival (P<0.000 1). In parallel, MPTP induced a pronounced increase in ROS levels and a significant reduction in ATP content, indicating severe mitochondrial dysfunction and energy metabolism impairment (P<0.01). TMAS treatment significantly improved motor performance, as reflected by the reversal of MPTP-induced impairment in the open-field and pole tests, and significantly reduced ROS accumulation (P<0.01) while restoring ATP production (P<0.001). At the molecular level, MPTP markedly downregulated PINK1 and Parkin, decreased p62 expression, increased LC3-II accumulation, elevated Drp1 expression, and reduced Opa1 expression, whereas TMAS significantly reversed these abnormalities, suggesting restoration of mitophagy-related mitochondrial quality control and re-establishment of mitochondrial fission-fusion balance. Collectively, these findings indicate that TMAS ameliorates MPTP-induced neurotoxicity and restores mitochondrial homeostasis and energy metabolism. ConclusionTMAS effectively attenuates neural damage and improves motor dysfunction in MPTP-induced PD mice. Its neuroprotective effects are closely associated with multidimensional regulation of the mitochondrial quality control system, including restoration of PINK1/Parkin-mediated mitophagy and rebalancing of Drp1/Opa1-related mitochondrial dynamics. Rather than acting only as a symptomatic neuromodulatory intervention, TMAS may influence a key pathological axis of PD by improving mitochondrial homeostasis in SNc and protecting nigral dopaminergic neurons. These findings provide experimental evidence supporting TMAS as a promising non-invasive physical intervention for PD.
7.Mechanism of Paeoniae Radix Rubra and Aconiti Lateralis Radix Praeparata in Treatment of Acute-on-chronic Liver Failure Based on Bioinformation Analysis and Experimental Validation
Xiaoling TIAN ; Yu ZHANG ; Shan DU ; Mengsi WU ; Nianhua TAN ; Bin CHEN
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(1):156-165
ObjectiveTo explore the mechanism of action of Paeoniae Radix Rubra and Aconiti Lateralis Radix Praeparata (CSFZ) in the treatment of acute-on-chronic liver failure (ACLF) through network pharmacology, molecular docking, and animal experiments. MethodsNetwork pharmacology was used to identify potential targets and related signaling pathways for the treatment of ACLF with CSFZ. Molecular docking was used to examine the binding activity of the core components with corresponding key targets. An ACLF rat model was established by subcutaneous and tail vein injections of bovine serum albumin combined with lipopolysaccharide (LPS) + D-galactosamine (D-GalN) intraperitoneal injection. A normal control group (NC), a model group, a CSFZ group (CSFZ, 5.85 g·kg-1), and a hepatocyte growth-promoting granule group (HGFG, 4.05 g·kg-1) were set up in this study. Pathological changes in rat liver tissue were observed using hematoxylin and eosin (HE) and Masson staining. Enzyme-linked immunosorbent assay (ELISA) was used to detect the expression levels of interleukin-6 (IL-6), B-cell lymphoma-2 (Bcl-2), Caspase-3, and albumin (ALB). Real-time quantitative polymerase chain reaction (Real-time PCR) and Western blot were used to measure the mRNA and protein expression levels of phosphoinositide 3-kinase (PI3K), protein kinase B (Akt), phosphorylated PI3K (p-PI3K), and phosphorylated Akt (p-Akt). ResultsNetwork pharmacology screening identified 49 active ingredients of CSFZ, 103 action targets, and 3 317 targets related to ACLF. Among these, 74 targets overlapped with CSFZ drug targets. Key nodes in the protein-protein interaction (PPI) network included Akt1, tumor necrosis factor (TNF), IL-6, Bcl-2, and Caspase-3. Gene Ontology (GO) functional analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis identified multiple signaling pathways, with the PI3K/Akt signaling pathway being the most frequent. Molecular docking showed that the core components of the drug exhibited good binding activity with the corresponding key targets. Animal experiments confirmed that CSFZ significantly improved liver tissue pathological damage in ACLF rats, reduced the release of inflammatory factors and liver cell apoptosis, and upregulated the expression levels of the PI3K/Akt signaling pathway. ConclusionThrough network pharmacology, molecular docking, and in vivo experiments, this study confirms the effect of CSFZ in reducing liver cell inflammatory damage and inhibiting liver cell apoptosis. The specific mechanism may be related to its involvement in regulating the PI3K/Akt signaling pathway.
8.Advances of Metal-Organic Framework Stationary Phases for Gas Chromatographic Separations
Yan JIN ; Wen-Bo LI ; Yu-Chen ZHU ; Bin ZHAO ; Lei LI ; Dan ZHENG ; Fei FENG
Chinese Journal of Analytical Chemistry 2025;53(1):1-13
Metal-organic frameworks(MOFs)are porous materials composed of metal ions or metal clusters and organic ligands by coordination,which have the advantages of large specific surface area,good thermal stability and adjustable pore size,and have a promising application in gas chromatographic separation.In recent years,MOFs materials have been used as stationary phases for gas chromatography mainly including ZIF,MIL,UiO-66,HKUST-1,IRMOFs,etc.Based on the molecular sieve effect,van der Waals forces,hydrogen bonding and π-π interactions,the pore size,pore microenvironment,unsaturated metal site and special functional group of the MOFs stationary phase materials can be specifically designed and regulated.MOFs materials as stationary phases have unique separation performance for n-alkanes and their isomers,aromatic compounds and their isomers,alcohols/ketones/aldehydes and their isomers,and chiral compounds.The combination of organic polymers and novel nanomaterials with MOFs materials can improve the separation performance and stability of MOFs.Therefore,MOFs materials are expected to be the promising stationary phase that can be applied to gas separation in complex environments.In this article,the research advances of various stationary phases based on MOFs for gas chromatography in recent years were reviewed.The separation performance and separation mechanism of MOFs stationary phases for mixed gas samples were discussed,and the development trends in the future were prospected.
9.Preparation and In Vitro Degradation Characteristics Analysis of Poly(lactic-co-glycolide)Microspheres Based on Microfluidic Process
Bao-Cheng WANG ; Cong-Yu MA ; Ke WANG ; Si-Tong ZHENG ; Xiao-Yan ZHANG ; Yue-Mei ZHAO ; Xun ZHAO ; Jian-Bin PAN ; Zheng-Song GAO ; Hai-Wei SHI ; Yao-Zuo YUAN ; Hong-Yuan CHEN
Chinese Journal of Analytical Chemistry 2025;53(4):621-630
Poly(lactic-co-glycolide)(PLGA)is a key excipient in long-acting sustained-release preparations,and its degradation properties directly affect the drug release behavior.In this study,PLGA microspheres were prepared by microfluidic techniques,and the morphology changes of the microspheres were observed by scanning electron microscopy(SEM).In alkaline environment,due to the accelerated hydrolysis of ester bonds,the surface of the microspheres was rapidly dissolved and eroded,and the degradation rate was significantly higher than that in acidic environment.High temperature accelerated the degradation of PLGA microspheres.Under neutral and alkaline conditions,the microspheres showed aggregation and adhesion.Under acidic conditions,the microspheres gradually decomposed into irregular fragments.The high ionic strength further promoted the surface corrosion of the microspheres,especially under extreme pH conditions.Simultaneously,PLGA microspheres encapsulating coumarin were prepared to simulate the microsphere formulation.The release rate of coumarin after degradation of the microspheres under different conditions was observed by measuring the absorbance with ultraviolet-visible spectrophotometry.The results were consistent with those of the blank microspheres.This study revealed that the degradation of PLGA microspheres was significantly pH-dependent,temperature sensitive and ion strength responsive.These findings not only helped to understand and optimize the long-term stability and controlled release performance of drug-carrying microspheres,but also provided a theoretical basis for further improvement of PLGA-based drug carrier design.
10.A Pneumatic Micro-valve with Sandwich Structure Based on Micro-electro-mechanical System
Shao-Jie MA ; Wen-Bo LI ; Yu-Chen ZHU ; Zhi-Rui LI ; Bin ZHAO ; Fei FENG
Chinese Journal of Analytical Chemistry 2025;53(5):758-764
In this study,an ON/OFF type micro-valve with a sandwich(glass-silicon-glass)structure was designed and fabricated based on the micro-electro-mechanical system(MEMS)technique.The deformable membrane of this micro-valve was prepared on the silicon on insulator(SOI)substrate and sealed using Si-Si bonding and anodic bonding methods.The micro-valve had high-temperature stability and was suitable for integration with other gas chromatography components.The deformable membrane with a thickness of 10 μm was processed on the top silicon of the SOI substrate.The flow control of the micro-valve could be achieved by changing the driving pressure applied to the deformable membrane to deform it.Compared with polymer membranes,the deformable membrane prepared on the top layer silicon of SOI had better temperature stability and could be released using the deep reactive ion etching technique after silicon-silicon bonding,avoiding deformation during the preparation process.In addition,due to the small gap between the membrane and the inlet/outlet holes,the dead volume of the microvalve was very small.The test results indicated that the micro-valve achieved flow control and ON/OFF functions with good repeatability.


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