Implanted neural probes can detect weak discharges of neurons in the brain by piercing soft brain tissue,thus as important tools for brain science research,as well as diagnosis and treatment of brain diseases.However,...Implanted neural probes can detect weak discharges of neurons in the brain by piercing soft brain tissue,thus as important tools for brain science research,as well as diagnosis and treatment of brain diseases.However,the rigid neural probes,such as Utah arrays,Michigan probes,and metal microfilament electrodes,are mechanically unmatched with brain tissue and are prone to rejection and glial scarring after implantation,which leads to a significant degradation in the signal quality with the implantation time.In recent years,flexible neural electrodes are rapidly developed with less damage to biological tissues,excellent biocompatibility,and mechanical compliance to alleviate scarring.Among them,the mechanical modeling is important for the optimization of the structure and the implantation process.In this review,the theoretical calculation of the flexible neural probes is firstly summarized with the processes of buckling,insertion,and relative interaction with soft brain tissue for flexible probes from outside to inside.Then,the corresponding mechanical simulation methods are organized considering multiple impact factors to realize minimally invasive implantation.Finally,the technical difficulties and future trends of mechanical modeling are discussed for the next-generation flexible neural probes,which is critical to realize low-invasiveness and long-term coexistence in vivo.展开更多
In this paper, a silicon-based neural probe with microfluidic channels was developed and evaluated. The probe can deliver chemicals or drugs to the target neurons while simultaneously recording the electrical action o...In this paper, a silicon-based neural probe with microfluidic channels was developed and evaluated. The probe can deliver chemicals or drugs to the target neurons while simultaneously recording the electrical action of these neurons extracellularly. The probe was fabricated by double-sided deep reactive ion etching （DRIE） from a silicon-on-insulator （SO1） wafer. The flu- idic channels were formed with V-shape groove etching on the silicon probe and sealed with silicon nitride and parylene-C. The shank of the probe is 4 mm long and 120 ~tm wide. The thickness of the probe is 100 ~tm. The probe has two fluidic chan- nels and two recording sites. The microfluidic channels can withstand a pressure drop as much as 30 kPa and the flow resisti ity of the microfluidic channel is 0.13 μL min-1 kPa-1, The typical impedance of the neural electrode is 32.3 kΩ at 1 kHz at room temperature.展开更多
Compared with stiff silicon-based probes,flexible neural probes can alleviate biological inflammation and tissue rejection.A polyethylene glycol(PEG)coating can facilitate the insertion of flexible probes,and the fabr...Compared with stiff silicon-based probes,flexible neural probes can alleviate biological inflammation and tissue rejection.A polyethylene glycol(PEG)coating can facilitate the insertion of flexible probes,and the fabrication methods have a significant impact on the dimensional accuracy and structural strength of the coating.In this study,a novel melting injection moulding method is used to process a PEG-dexamethasone(PEG-DEX)coating with high structural strength for a type of mesh-shaped photosensitive polyimide(PSPI)based neural probe.Combined with the digital image correlation(DIC)method,an in vitro test system with high accuracy is developed to evaluate the effects of the elastic modulus of the PEG component and two fabrication methods,i.e.,computer-numerical-control(CNC)micro-milling and laser engraving,on the processing quality and implantation mechanics of a PEG-DEX coated probe.The results show that compared with laser engraving,CNC micro-milling can ensure high dimensional accuracy and sharpness for the composite coating,thus leading to small damage from implantation,whereas the elastic modulus of the composite coating has a limited effect on the implantation mechanics of the PEG-DEX coated probe.展开更多
Silicon-on-insulator(SOI) substrate is widely used in micro-electro-mechanical systems(MEMS).With the buried oxide layer of SOI acting as an etching stop,silicon based micro neural probe can be fabri-cated with improv...Silicon-on-insulator(SOI) substrate is widely used in micro-electro-mechanical systems(MEMS).With the buried oxide layer of SOI acting as an etching stop,silicon based micro neural probe can be fabri-cated with improved uniformity and manufacturability.A seven-record-site neural probe was formed by inductive-coupled plasma(ICP) dry etching of an SOI substrate.The thickness of the probe is 15 μm.The shaft of the probe has dimensions of 3 mm×100 μm×15 μm with typical area of the record site of 78.5 μm2.The impedance of the record site was measured in-vitro.The typical impedance characteris-tics of the record sites are around 2 MΩ at 1 kHz.The performance of the neural probe in-vivo was tested on anesthetic rat.The recorded neural spike was typically around 140 μV.Spike from individual site could exceed 700 μV.The average signal noise ratio was 7 or more.展开更多
提出一种基于NARX(Nonlinear Auto-Regressive Model with Exogenous Inputs)神经网络和谐波探测法的非线性系统传递函数识别方法。该方法可基于实测响应数据,采用NARX神经网络方法对结构响应模型进行训练。在此基础上采用谐波探测法得...提出一种基于NARX(Nonlinear Auto-Regressive Model with Exogenous Inputs)神经网络和谐波探测法的非线性系统传递函数识别方法。该方法可基于实测响应数据,采用NARX神经网络方法对结构响应模型进行训练。在此基础上采用谐波探测法得到系统响应传递函数。选取深海半潜浮式平台及系泊系统为研究对象,计算平台及其系泊系统在不同波浪工况作用下的时域耦合响应,以波高和系泊缆张力时程作为数据集,利用NARX神经网络结合谐波探测法辨识此系泊系统的响应传递函数。采用识别的传递函数预测系泊缆在不同海况下的张力响应,并与数值计算结果进行对比,证明NARX神经网络结合谐波探测法可较好地识别系泊浮体系统的非线性响应传递函数,并能够对系泊系统的张力响应进行准确预测。展开更多
基金support received from the National Natural Science Foundation of China(GrantNos.62204204 and 52175148)Science and Technology Innovation 2030-Major Project(Grant No.2022ZD0208601)+1 种基金Shanghai Sailing Program(Grant No.21YF1451000)Presidential Foundation of CAEP(Grant No.YZJJZQ2022001).
文摘Implanted neural probes can detect weak discharges of neurons in the brain by piercing soft brain tissue,thus as important tools for brain science research,as well as diagnosis and treatment of brain diseases.However,the rigid neural probes,such as Utah arrays,Michigan probes,and metal microfilament electrodes,are mechanically unmatched with brain tissue and are prone to rejection and glial scarring after implantation,which leads to a significant degradation in the signal quality with the implantation time.In recent years,flexible neural electrodes are rapidly developed with less damage to biological tissues,excellent biocompatibility,and mechanical compliance to alleviate scarring.Among them,the mechanical modeling is important for the optimization of the structure and the implantation process.In this review,the theoretical calculation of the flexible neural probes is firstly summarized with the processes of buckling,insertion,and relative interaction with soft brain tissue for flexible probes from outside to inside.Then,the corresponding mechanical simulation methods are organized considering multiple impact factors to realize minimally invasive implantation.Finally,the technical difficulties and future trends of mechanical modeling are discussed for the next-generation flexible neural probes,which is critical to realize low-invasiveness and long-term coexistence in vivo.
基金supported by the National Basic Research Program of China("973" Project) (Grant Nos. 2011CB933203, 2011CB933102)the National Natural Science Foundation of China (Grant Nos.31070965,90820002,60877035,60976026 and 61076023)
文摘In this paper, a silicon-based neural probe with microfluidic channels was developed and evaluated. The probe can deliver chemicals or drugs to the target neurons while simultaneously recording the electrical action of these neurons extracellularly. The probe was fabricated by double-sided deep reactive ion etching （DRIE） from a silicon-on-insulator （SO1） wafer. The flu- idic channels were formed with V-shape groove etching on the silicon probe and sealed with silicon nitride and parylene-C. The shank of the probe is 4 mm long and 120 ~tm wide. The thickness of the probe is 100 ~tm. The probe has two fluidic chan- nels and two recording sites. The microfluidic channels can withstand a pressure drop as much as 30 kPa and the flow resisti ity of the microfluidic channel is 0.13 μL min-1 kPa-1, The typical impedance of the neural electrode is 32.3 kΩ at 1 kHz at room temperature.
基金the National Natural Science Foundation of China(No.51675330)。
文摘Compared with stiff silicon-based probes,flexible neural probes can alleviate biological inflammation and tissue rejection.A polyethylene glycol(PEG)coating can facilitate the insertion of flexible probes,and the fabrication methods have a significant impact on the dimensional accuracy and structural strength of the coating.In this study,a novel melting injection moulding method is used to process a PEG-dexamethasone(PEG-DEX)coating with high structural strength for a type of mesh-shaped photosensitive polyimide(PSPI)based neural probe.Combined with the digital image correlation(DIC)method,an in vitro test system with high accuracy is developed to evaluate the effects of the elastic modulus of the PEG component and two fabrication methods,i.e.,computer-numerical-control(CNC)micro-milling and laser engraving,on the processing quality and implantation mechanics of a PEG-DEX coated probe.The results show that compared with laser engraving,CNC micro-milling can ensure high dimensional accuracy and sharpness for the composite coating,thus leading to small damage from implantation,whereas the elastic modulus of the composite coating has a limited effect on the implantation mechanics of the PEG-DEX coated probe.
基金Supported by the National Basic Research Program of China ("973" Project) (Grant No. 2005CB724302)the National High-Tech Research and Development Program of China ("863" Project) (Grant Nos. 2007AA04Z329, 2007AA03Z427)the National Natural Science Foundation of China (Grant No. 60776024)
文摘Silicon-on-insulator(SOI) substrate is widely used in micro-electro-mechanical systems(MEMS).With the buried oxide layer of SOI acting as an etching stop,silicon based micro neural probe can be fabri-cated with improved uniformity and manufacturability.A seven-record-site neural probe was formed by inductive-coupled plasma(ICP) dry etching of an SOI substrate.The thickness of the probe is 15 μm.The shaft of the probe has dimensions of 3 mm×100 μm×15 μm with typical area of the record site of 78.5 μm2.The impedance of the record site was measured in-vitro.The typical impedance characteris-tics of the record sites are around 2 MΩ at 1 kHz.The performance of the neural probe in-vivo was tested on anesthetic rat.The recorded neural spike was typically around 140 μV.Spike from individual site could exceed 700 μV.The average signal noise ratio was 7 or more.
文摘提出一种基于NARX(Nonlinear Auto-Regressive Model with Exogenous Inputs)神经网络和谐波探测法的非线性系统传递函数识别方法。该方法可基于实测响应数据,采用NARX神经网络方法对结构响应模型进行训练。在此基础上采用谐波探测法得到系统响应传递函数。选取深海半潜浮式平台及系泊系统为研究对象,计算平台及其系泊系统在不同波浪工况作用下的时域耦合响应,以波高和系泊缆张力时程作为数据集,利用NARX神经网络结合谐波探测法辨识此系泊系统的响应传递函数。采用识别的传递函数预测系泊缆在不同海况下的张力响应,并与数值计算结果进行对比,证明NARX神经网络结合谐波探测法可较好地识别系泊浮体系统的非线性响应传递函数,并能够对系泊系统的张力响应进行准确预测。
