Project: MiniFAB Microfluidic Tear Sensor
MiniFAB is a privately owned micro and nano fabrication company based in Melbourne, Australia.
MiniFAB developed and manufactures the Tear Sensor for its client, OcuSense (San Diego, California) who market the product as TearLab in Europe.
The R&D was conducted using MiniFAB’s Staged Development Plan and the time taken to move from basic proof-of-concept research to fully certified production was less than 20 months.
The Tear Sensor is a single use, disposable microfluidic device that uses capillary forces to collect exactly 50 nl of tear sample from the patient.
Within a few seconds an electrical measurement is performed to determine the osmolarity of the tear providing a diagnosis for Dry Eye condition.
All manufacturing processes are performed under ISO13485 Clean Room conditions with extensive Quality Control to ensure better than 1.5% CV performance.
The critical microfluidic channel is injection moulded to create a 75µm (µm is micrometers) deep 1mm long profiled-structure.
Gold sputtering and high resolution excimer laser ablation using a custom designed high throughput system is used to create precision electrodes in the microfluidic channel.
In order to meet the performance specification all manufacturing processes must be controlled to sub-1% tolerances. This translates to reproducing mechanical tolerances in the nanometre range.