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Stick-packaging of goods in tubular shaped composite-foil pouches has become a popular technology for food packaging. We miniaturized stick-packaging for use in Lab-on-a-Chip (LOAC) systems to pre-store and release liquid and dry reagents in a volume range of 80 -500 μl. A frangible seal integrated in the package allows for the pressure-controlled release of reagents, reducing the number of downstream valves required for liquid control. The frangible seal is fabricated by ultrasonic welding, enabling adjustment of burst pressures from 20 to 100 kPa, and allowing for packaging of temperature sensitive reagents. As an additional advantage, stick-packaging is also a scalable technology suitable for both rapid prototyping and low-cost mass production.

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The lamination of different polyethylene (PE) composite films by ultrasonic welding to fabricate peelable seals that open at defined burst pressures is investigated. The sealing time, pressure, and amplitude were varied within the range of 100–400 ms, 50–250 kPa, and 12–24 µm, respectively. T‐peel tests and electron micrographs revealed four different peel regimes, depending on the parameter combination: (I) Interlaminar peeling at low‐peel strength with uniform peeling along a weakly bonded PE lamination layer; (II) transition tearing at intermediate peel strength showing areas of interlaminar peeling and translaminar tearing; (III) translaminar tearing at high‐peel strength showing tears through the entire film; and, (IV) undefined tearing at varying tear strength occurring when vibration effects during welding lead to insufficient contact of the films or high pressures lead to a displacement of PE. This study will allow the systematic adjustment of ultrasonic welding parameters for PE films. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40291.

We developed a system for the detection of botulinum neurotoxin (BoNT) type A based on a highly sensitive luciferase reporter assay automated by the centrifugal microfluidic LabDisk platform. The assay is based on the detection of BoNT's proteolytic activity and generation of a bioluminescent signal due to the release of firefly luciferase, pre-bound to microbeads via a cleavable peptide linker, in response to BoNT. It detected purified BoNT, BoNT in complex with neurotoxin associated proteins, and the recombinant enzymatic BoNT light chain in buffer and whole milk in the concentration range of 8 pM to 6 nM with an analytical sensitivity and limit of detection of 10-39 pM and 6-14 pM, respectively. The intra-disk, intra-day and inter-day variability were in the range of 1-13%, 1-7% and 10-13%, respectively. The developed assay correlated well with the conventional microwell plate assay. It is superior to the conventional BoNT assays in terms of portability, cost-effectiveness, lesser sample requirement, lesser number of steps and detection of a broad spectrum of BoNT serotypes and subtypes. It takes only 30 minutes, which is ideal for point-of-need BoNT detection in the case of security threats and food monitoring.