Micro-droplet jetting belongs to the field of precision fluid dispensing techniques.Unlike traditional subtraction manufacture process,micro-droplet jetting as an additive fabrication technique with features of non-co...Micro-droplet jetting belongs to the field of precision fluid dispensing techniques.Unlike traditional subtraction manufacture process,micro-droplet jetting as an additive fabrication technique with features of non-contact and data-driven represents a new development trend of modern manufacturing process.In this paper,the design,fabrication and performance of a multi-materials drop-on-demand (DOD) inkjet system based on pneumatic diaphragm actuator were described.For capturing the droplet ejection process and measuring the droplet dimension,a self-made in situ imaging system based on time delayed external trigger was set up.The performance of the generator was studied by adjusting the structure and control parameters.Furthermore,the influence of fluid properties on the droplet ejection process was experimentally investigated.Micro-solderballs of 160.5 μm in diameter and UV curing adhesive micro-bumps of 346.94 μm in contact diameter with the substrate were produced.The results demonstrated that the DOD inkjet generator possesses characteristics of robust,easy to operate and maintain,and able to withstand high temperature as well as applicability to a wide variety of materials including polymers,low melting point resin and high melting point metal.The system has a great potential of being used in the fields of IC and MEMS packaging,3D printing,organic semiconductor fabrication,and biological and chemical analysis.展开更多
The establishment of highly sensitive diagnostic methods is critical in the early diagnosis and control of Zika virus(ZIKV)and in preventing serious neurological complications of ZIKV infection. In this study, we esta...The establishment of highly sensitive diagnostic methods is critical in the early diagnosis and control of Zika virus(ZIKV)and in preventing serious neurological complications of ZIKV infection. In this study, we established micro-droplet digital polymerase chain reaction(ddPCR) and real-time quantitative PCR(RT-qPCR) protocols for the detection of ZIKV based on the amplification of the NS5 gene. For the ZIKV standard plasmid, the RT-qPCR results showed that the cycle threshold(Ct) value was linear from 10~1 to 10~8 copy/l L, with a standard curve R^2 of 0.999 and amplification efficiency of 92.203%;however, a concentration as low as 1 copy/l L could not be detected. In comparison with RT-qPCR, the dd PCR method resulted in a linear range of 10~1–10~4 copy/l L and was able to detect concentrations as low as 1 copy/l L. Thus, for detecting ZIKV from clinical samples, RT-qPCR is a better choice for high-concentration samples(above 10~1 copy/l L),while ddPCR has excellent accuracy and sensitivity for low-concentration samples. These results indicate that the ddPCR method should be of considerable use in the early diagnosis, laboratory study, and monitoring of ZIKV.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 50775087)
文摘Micro-droplet jetting belongs to the field of precision fluid dispensing techniques.Unlike traditional subtraction manufacture process,micro-droplet jetting as an additive fabrication technique with features of non-contact and data-driven represents a new development trend of modern manufacturing process.In this paper,the design,fabrication and performance of a multi-materials drop-on-demand (DOD) inkjet system based on pneumatic diaphragm actuator were described.For capturing the droplet ejection process and measuring the droplet dimension,a self-made in situ imaging system based on time delayed external trigger was set up.The performance of the generator was studied by adjusting the structure and control parameters.Furthermore,the influence of fluid properties on the droplet ejection process was experimentally investigated.Micro-solderballs of 160.5 μm in diameter and UV curing adhesive micro-bumps of 346.94 μm in contact diameter with the substrate were produced.The results demonstrated that the DOD inkjet generator possesses characteristics of robust,easy to operate and maintain,and able to withstand high temperature as well as applicability to a wide variety of materials including polymers,low melting point resin and high melting point metal.The system has a great potential of being used in the fields of IC and MEMS packaging,3D printing,organic semiconductor fabrication,and biological and chemical analysis.
基金supported by the National Natural Science Foundation of China (Nos. 31470271 and 81730110)Guangzhou Science and Technology Program key projects (No. 201803040006)
文摘The establishment of highly sensitive diagnostic methods is critical in the early diagnosis and control of Zika virus(ZIKV)and in preventing serious neurological complications of ZIKV infection. In this study, we established micro-droplet digital polymerase chain reaction(ddPCR) and real-time quantitative PCR(RT-qPCR) protocols for the detection of ZIKV based on the amplification of the NS5 gene. For the ZIKV standard plasmid, the RT-qPCR results showed that the cycle threshold(Ct) value was linear from 10~1 to 10~8 copy/l L, with a standard curve R^2 of 0.999 and amplification efficiency of 92.203%;however, a concentration as low as 1 copy/l L could not be detected. In comparison with RT-qPCR, the dd PCR method resulted in a linear range of 10~1–10~4 copy/l L and was able to detect concentrations as low as 1 copy/l L. Thus, for detecting ZIKV from clinical samples, RT-qPCR is a better choice for high-concentration samples(above 10~1 copy/l L),while ddPCR has excellent accuracy and sensitivity for low-concentration samples. These results indicate that the ddPCR method should be of considerable use in the early diagnosis, laboratory study, and monitoring of ZIKV.
