A sequential injection analysis (SIA) system based on polydimethylsiloxane (PDMS) chip with integrated pneumatic-actuated valves was developed. A novel SIA operation mode using multiphase laminar flow effect and pneum...A sequential injection analysis (SIA) system based on polydimethylsiloxane (PDMS) chip with integrated pneumatic-actuated valves was developed. A novel SIA operation mode using multiphase laminar flow effect and pneumatic microvalve control was proposed. The sample and reagent solutions were synchronously loaded and injected in the chip-based sample injection module instead of multi-step sequential injection by a multiposition valve and a reciprocating pump as in conventional SIA system. The sample and reagent injection volumes were reduced to ca. 1.1 nL. The present system has the advantages of simple structure, fast and convenient operation, low sample and reagent consumption, and high degree of integration and automation. The system operation conditions were optimized using fluorescein as model sample. Its feasibility in biological analysis was preliminarily demonstrated in enzyme inhibition assay.展开更多
Based on flip-chip packaging,a novel approach towards integrated magnetic bio-separator was designed.The magnetic field and the force on the bead were simulated and analyzed,leading to the optimization of the fabricat...Based on flip-chip packaging,a novel approach towards integrated magnetic bio-separator was designed.The magnetic field and the force on the bead were simulated and analyzed,leading to the optimization of the fabrication parameters of the micro-magnetic unit.The planar coil as an electromagnet was fabricated through electroplating on a single seed layer. The PDMS microfluidic channel was bonded on the inverse side after Si etching.The results presented in this paper provide a novel design and fabrication to approach a microfluidic bio-separation system with magnetic beads.展开更多
This paper discusses the fabrication of Si-PDMS low voltage capillary electrophoresis chip (CE chip). Arrayed-electrode which is used to apply low separation voltage is fabricated along the sidewalls of the separation...This paper discusses the fabrication of Si-PDMS low voltage capillary electrophoresis chip (CE chip). Arrayed-electrode which is used to apply low separation voltage is fabricated along the sidewalls of the separation channel on the silicon based bottom part. Isolation trenches, which are placed surrounding the arrayed-electrode, insure the insulation between the arrayed-electrode, as well as arrayed-electrode and liquid in the micro channel. Polydimethylsilicone (PDMS) is used as the cover. PDMS and silicon based bottom part are reversible sealed to attain Si-PDMS low voltage CE chip. Experiments have been done to obtain optimum electrophoresis separation condition: separation voltage is 45V, switch time is 2s and the Phe and Lys electrophoresis separation is successful.展开更多
In vivo 3D fluorescent image remains a technological barrier for biologists and clinical scientists although green fluorescent protein(GFP)imaging has long been performed rather well at cellular level.Meanwhile,robust...In vivo 3D fluorescent image remains a technological barrier for biologists and clinical scientists although green fluorescent protein(GFP)imaging has long been performed rather well at cellular level.Meanwhile,robust enough portable devices are also challenging lab-on-a-chip advocators who wish their designs to be nurtured by the end users.This work is dedicated to propose a conceptually innovated transparent soft PDMS avian eggshell to directly tackle the above two goals.Here,an"egg-on-a-chip"scheme is originally developed and demonstrated by a newly developed PDMS"soft"process method.Unlike its ancestor–the conventional"lab-on-a-chip"(LOC)which is basically chemically based,the current"egg-on-a-chip",intrinsically inherited with biological natures,opens a way to integrate biological parts or whole system in a miniature sized device.Such biomimics system contains much condensed environmental evolutional tensor inside than those of the existing LOC compacted with artificial components which however are quite difficult to incorporate various life factors inside.Owning unique advantages,a series of transparent PDMS whole"eggshells"have been fabricated and applied to culture avian embryos up to 17.5 days and chimeric eggshells were engineered on normal eggs.In addition,X-stage embryos were successfully initiated in such system and pre-chorioallantoic membrane was observed.Further,limitation of the present process was interpreted and potential approach to improve it was suggested.With both high optical transparency and engineering subtlety fully integrated together,the present method not only provides an ideal transparent imaging platform for studying functional embryo development including life mystery,but also promises a future strategy for"lab-on-an-egg"technology which may be important in a wide variety of either fundamental or practical areas.展开更多
基金supported by the National Natural Science Foundation of China (20825517, 20890020)Ministry of Science and Technology of China (2007CB714503)
文摘A sequential injection analysis (SIA) system based on polydimethylsiloxane (PDMS) chip with integrated pneumatic-actuated valves was developed. A novel SIA operation mode using multiphase laminar flow effect and pneumatic microvalve control was proposed. The sample and reagent solutions were synchronously loaded and injected in the chip-based sample injection module instead of multi-step sequential injection by a multiposition valve and a reciprocating pump as in conventional SIA system. The sample and reagent injection volumes were reduced to ca. 1.1 nL. The present system has the advantages of simple structure, fast and convenient operation, low sample and reagent consumption, and high degree of integration and automation. The system operation conditions were optimized using fluorescein as model sample. Its feasibility in biological analysis was preliminarily demonstrated in enzyme inhibition assay.
文摘Based on flip-chip packaging,a novel approach towards integrated magnetic bio-separator was designed.The magnetic field and the force on the bead were simulated and analyzed,leading to the optimization of the fabrication parameters of the micro-magnetic unit.The planar coil as an electromagnet was fabricated through electroplating on a single seed layer. The PDMS microfluidic channel was bonded on the inverse side after Si etching.The results presented in this paper provide a novel design and fabrication to approach a microfluidic bio-separation system with magnetic beads.
文摘This paper discusses the fabrication of Si-PDMS low voltage capillary electrophoresis chip (CE chip). Arrayed-electrode which is used to apply low separation voltage is fabricated along the sidewalls of the separation channel on the silicon based bottom part. Isolation trenches, which are placed surrounding the arrayed-electrode, insure the insulation between the arrayed-electrode, as well as arrayed-electrode and liquid in the micro channel. Polydimethylsilicone (PDMS) is used as the cover. PDMS and silicon based bottom part are reversible sealed to attain Si-PDMS low voltage CE chip. Experiments have been done to obtain optimum electrophoresis separation condition: separation voltage is 45V, switch time is 2s and the Phe and Lys electrophoresis separation is successful.
基金supported by the National Natural Science Foundation of China(Grant No.51376102)
文摘In vivo 3D fluorescent image remains a technological barrier for biologists and clinical scientists although green fluorescent protein(GFP)imaging has long been performed rather well at cellular level.Meanwhile,robust enough portable devices are also challenging lab-on-a-chip advocators who wish their designs to be nurtured by the end users.This work is dedicated to propose a conceptually innovated transparent soft PDMS avian eggshell to directly tackle the above two goals.Here,an"egg-on-a-chip"scheme is originally developed and demonstrated by a newly developed PDMS"soft"process method.Unlike its ancestor–the conventional"lab-on-a-chip"(LOC)which is basically chemically based,the current"egg-on-a-chip",intrinsically inherited with biological natures,opens a way to integrate biological parts or whole system in a miniature sized device.Such biomimics system contains much condensed environmental evolutional tensor inside than those of the existing LOC compacted with artificial components which however are quite difficult to incorporate various life factors inside.Owning unique advantages,a series of transparent PDMS whole"eggshells"have been fabricated and applied to culture avian embryos up to 17.5 days and chimeric eggshells were engineered on normal eggs.In addition,X-stage embryos were successfully initiated in such system and pre-chorioallantoic membrane was observed.Further,limitation of the present process was interpreted and potential approach to improve it was suggested.With both high optical transparency and engineering subtlety fully integrated together,the present method not only provides an ideal transparent imaging platform for studying functional embryo development including life mystery,but also promises a future strategy for"lab-on-an-egg"technology which may be important in a wide variety of either fundamental or practical areas.
