Repeatable, Low-Cost UV Assembly of Biosensors

EXFO, Ontario, Canada

A biosensor is an analytical device that converts a biological response into an electrical signal. It is increasingly being used as a cost-effective diagnostic tool that offers the capability to render efficient, easy-to-use, and accurate diagnosis. While technological advances in biosensors are allowing this technology to cater to an extensive range of applications in a number of fields, such as industrial and environmental testing, the largest applications have been in the healthcare sector, including glucose detection, pregnancy testing, blood testing, breath analyzers, and cancer diagnosis.

The **OmniCure® S2000 UV spot curing system** may be applied to both automated and manual adhesive curing processes and cures UV acrylics in seconds.

Glucose detection is the most widely used application of a biosensor, driven by the increasing incidence of Type 2 diabetes in both developed and emerging markets. Manufacturing of a biosensor typically includes assembly of the components in multiple layers. The detector element is placed on an insulating base, followed by a precisely designed dielectric or insulating layer and finally a reagent layer. The function of the reagent layer is to convert glucose, or another analyte, into a chemical species that is measurable by the detector element. The function of the dielectric pattern is to insulate the detector element from the test sample except in a specifically defined area in order to enhance the reproducibility of the sensor reading.

A precisely defined area is important because the measurement of the sensor is dependent on both the concentration of the analyte and the area of the detector element that is exposed to the test sample. Therefore, it is very important that this defined area is consistent and repeatable in the manufacturing process in order to achieve consistent and repeatable readings between biosensors. A dielectric layer can be reproducibly fabricated using specialized UV-curable acrylates.

The OmniCure® S2000 UV spot curing system may be applied to both automated and manual adhesive curing processes and cures UV acrylics in seconds. The closed-loop feedback technology ensures repeatable irradiance levels. It includes a lamp with a dichroic filter to virtually eliminate IR light for a low-heat curing process. Five different filter options provide further low-heat curing for sensitive components. The 200W UV lamp technology offers up to 30 W/cm2 of output and a 2000-hour lamp life.

Over time, lamp intensity may diminish effective curing. To address this problem, the spot curing system features an internal intensity sensor that monitors light output in real time, and opens the iris to automatically correct light output within ±5%, ensuring repeatable and measurable doses of energy. A PLC/audible alarm warns when the lamp can no longer generate the set irradiance level. Calibration with the OmniCure® R2000 Radiometer offers real time display of irradiance on the OmniCure® S2000. It can be calibrated in real time for NIST accuracy.

This technology was done by OmniCure® by Lumen Dynamics, Ontario, Canada. For more information, please visit http://info.hotims.com/28059-152 .