Signed and sealed: Enabling optimised microfluid diagnostic platforms
Rick Crane, Innovation Services Group, J-Pac Medical explains how frangible and burst seal technology enables optimised microfluidic diagnostic platforms.
Microfluidics technology allows for extremely precise, small volumes of fluids to be dispensed via micro-scale devices. This has many implications for the medical market – particularly in regard to diagnostic applications. Microfluidic diagnostic platforms utilising on-chip reagent blisters help eliminate multi-step lab processes where human error and instrument contamination are most likely to occur, and expands the opportunities for diagnostics testing and monitoring to be performed from the convenience of a patient’s home or doctor’s office rather than necessitating a laboratory. This type of point-of-care (POC) testing is driven by continuous technology improvements and the recognition that rapid test results offer economic benefits and potential patient benefits due to faster turn-a-round of testing results.
More and more diagnostic device manufacturers see the value of easily incorporating burst and frangible seal reagent blister reservoirs into lateral flow and lab-on-a-chip/card formats, providing significant cost savings as an alternative to the conventional eyedropper and bottled reagent systems with an added reassurance of test reliability. By integrating frangible seal technology into on-board reagent blisters of POC devices, the device manufacturer is able to better control performance variability, reduce overall manufacturing and disposal costs, and simplify the end-user experience.
J-Pac Medical has made ongoing investments in unit-of-use reagent reservoirs and unit dose delivery systems that integrate into various microfluidicbased diagnostic products for stat testing applications. J-Pac Medical has developed two reagent delivery technologies in single or multi-well formats for common lab-on-chip formats: burst (pierce-able) and frangible seal blisters.
Burst blisters are typically used in applications where the test equipment pierces and evacuates the fluid. Frangible seal blister technology is used to deliver controlled release of reagents using J-Pac’s differential seal technology. By using differential weld strengths designed to fail under specific pressure, unit-of-use reagent reservoirs in customised formats can be integrated into many existing diagnostic test platforms, helping manufacturers to create new offerings without drastic changes in the product line.
This incorporation of on-board reagent blisters represents a new vision for improving the performance of microfluidics devices while at the same time reducing cost and offering a safe and reliable method for dispensing unit-of-measure volumes for diagnostic testing.
With some upfront consideration of the system dynamics, custom blister designs can be optimised and applied to an entire testing platform, lowering costs across the entire product family. J-Pac Medical’s reagent blisters are designed to offer a convenient way to bring new or improved diagnostic products to market quickly and affordably and its reagent blister development kits allow device manufacturers to test the use of lab-on-chip reagent blisters with their own microfluidic formats for diagnostic applications.
It is important that frangible seal manufacturers like J-Pac consider the specific requirements of every custom blister reservoir and design a blister solution that considers material compatibility, burst characteristics, reagent volume delivered, and long-term storage requirements. There are several different types of materials that can be used for reagent blisters and generally can be described as specialised foils and laminates used for cold- and thermo-formed packaging. These materials have various thicknesses and seal strengths that can be used for pierced or burst /push-through, peelable, and hybrid peel-push barriers.
J-Pac’s custom delivery systems are designed to meet specific product requirements (including directionality of flow), protect the product, assure sterile transfer and maintain consistently successful delivery to patients. Furthermore, its highly automated production methods ensure precise reagent filling for single and multiple-well formats, allowing tests to be consistent and reproducible - whether customers need 10,000 or ten million reagent blisters.
Depending on the form factor and release requirements, materials can be processed to create ‘frangible’ blister seal reservoirs with differential weld strengths designed and engineered to either be permanent or break, distort or yield on contact actuation or fail under a specific pressure. These weld strengths on the reservoir seals are a function of the material properties and applying unique welding processes that are combinations of pressure, temperature and time to meet the seal specification.
J-Pac’s understanding of these specialised material properties and processing capabilities allows it to ‘dial-in’ the specific burst strength needed for activation – though not fragile enough to rupture prematurely due to routine handling, assembly or shipping activities.
Demonstrating this flexibility, a single blister design can be created with a frequently used foil material set and then sealed using different processing parameters. The sealed blisters have been actuated and measured for the force required to release the contents. The graph below demonstrates three different populations of burst blisters were created reproducibly for different burst values by making adjustments in the processing parameters.