Integration of an Optical Ring Resonator Biosensor into a Self-Contained Microfluidic Cartridge with Active, Single-Shot Micropumps

While there have been huge advances in the field of biosensors during the last decade, their integration into a microfluidic environment avoiding external tubing and pumping is still neglected. Herein, we show a new microfluidic design that integrates multiple reservoirs for reagent storage and single-use electrochemical pumps for time-controlled delivery of the liquids. The cartridge has been tested and validated with a silicon nitride-based photonic biosensor incorporating multiple optical ring resonators as sensing elements and an immunoassay as a potential target application. Based on experimental results obtained with a demonstration model, subcomponents were designed and existing protocols were adapted. The newly-designed microfluidic cartridges and photonic sensors were separately characterized on a technical basis and performed well. Afterwards, the sensor was functionalized for a protein detection. The microfluidic cartridge was loaded with the necessary assay reagents. The integrated pumps were programmed to drive the single process steps of an immunoassay. The prototype worked selectively, but only with a low sensitivity. Further work must be carried out to optimize biofunctionalization of the optical ring resonators and to have a more suitable flow velocity progression to enhance the system’s reproducibility.The authors would like to thank the European Union for their funding of the project PBSA “Photonic Biosensor for Space Application” within the FP7-program (FP7 program Grant Agreement No. 312942-PBSA. We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI

Roll-to-Roll pilot line for large-scale manufacturing of microfluidic devices

Roll-to-roll (R2R) technologies with roller-based nanoimprinting methods enable manufacturing of highly cost-effective and large-scale sheets of flexible polymer film with precise structures on a micro- and nanoscale 1. Areas that can benefit strongly from such large scale technologies are microfluidics, biosensors, and lab-on-chip products for point of care diagnostics, drug discovery and food control. Here, R2R fabrication could greatly reduce production costs and increase manufacturing capacity with respect to currently used products. A pilot line with this technology is investigated in the European Horizon 2020 project R2R Biofluidics and its capabilities are tested on two Demonstrators: - Demonstrator 1: In-vitro diagnostic chip with imprinted microfluidic channels based on optical chemiluminescence measurement by photodetectors. - Demonstrator 2: Neuronal cell culture plate with imprinted cavities and channels for controlled culturing and fluorescence imaging of neurons, for high throughput drug screening. Please click Additional Files below to see the full abstract

Integration of an Optical Ring Resonator Biosensor into a Self-Contained Microfluidic Cartridge with Active, Single-Shot Micropumps

While there have been huge advances in the field of biosensors during the last decade, their integration into a microfluidic environment avoiding external tubing and pumping is still neglected. Herein, we show a new microfluidic design that integrates multiple reservoirs for reagent storage and single-use electrochemical pumps for time-controlled delivery of the liquids. The cartridge has been tested and validated with a silicon nitride-based photonic biosensor incorporating multiple optical ring resonators as sensing elements and an immunoassay as a potential target application. Based on experimental results obtained with a demonstration model, subcomponents were designed and existing protocols were adapted. The newly-designed microfluidic cartridges and photonic sensors were separately characterized on a technical basis and performed well. Afterwards, the sensor was functionalized for a protein detection. The microfluidic cartridge was loaded with the necessary assay reagents. The integrated pumps were programmed to drive the single process steps of an immunoassay. The prototype worked selectively, but only with a low sensitivity. Further work must be carried out to optimize biofunctionalization of the optical ring resonators and to have a more suitable flow velocity progression to enhance the system’s reproducibility

Capillary microfluidic chip with integrated pump and valve actuator: Poster presented at the 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014, October 26 - 30, 2014, San Antonio, Texas

Glycated Hemoglobin (HbA1c) is a long term blood glucose marker currently only available by laboratory testing. Main hurdle for point-of-care testing of HbA1c is the necessary on-chip sample preparation. One limiting factor is the lack of miniaturized, time-controlled liquid actuation functionality. In the presented concept electrochemical pumping in an active and disposable microfluidic lab-on-a-chip is used for the required flow control. In contrast to previous works the sample is directly used as working liquid for pumping and valving. A novel gelbased check valve approach is used to avoid undesired liquid movement towards the inlet of the chip. This method results in a miniaturization of the chip design and sample volume, the combination of passive and active microfluidics, and the elimination of external handling steps. The system utilizes well known technologies like hot embossing, physical vapor deposition (PVD) and laser micro machining to realize the innovative chip concept. The complex parameter HbA1c is supposed to be determined from a drop of capillary blood (5ìl) after a chip internal sample preparation step