Lab on a chip devices require testing standards
10 Aug 2012
The National Institute of Standards and Technology (NIST) has argued that testing standards need to be developed for lab on a chip technology.
Lab on a chip (LOC) devices that can prepare and analyse tiny fluid samples with volumes ranging from a few microliters (millionth of a liter) to sub-nanoliters (less than a billionth of a liter) – are envisioned to one day revolutionise how laboratory tasks.
However, a recent paper from the National Institute of Standards and Technology (NIST) argues that before LOC technology can be fully commercialised, testing standards need to be developed and implemented.
“A testing standard,” explained NIST physical scientist and paper author Samuel Stavis, “defines the procedures used to determine if a lab on a chip device, and the materials from which it is made, conform to specifications.”
Testing and measurement methods, Stavis writes, will enable MEMS (microelectromechanical systems) LOC manufacturers at all stages of production – from processing of raw materials to final rollout of products – to accurately determine important physical characteristics of LOC devices such as dimensions, electrical surface properties, and fluid flow rates and temperatures.
To make his case for testing standards, Stavis focuses on autofluorescence, the background fluorescent glow of an LOC device that can interfere with the analysis of a sample.
Stavis states that multiple factors must be considered in the development of a testing standard for autofluorescence, including: the materials used in the device, the measurement methods used to test the device and how the measurements are interpreted.
Quality control during LOC device manufacturing, Stavis says, may require different tests of autofluorescence throughout the process.
“There may be one measure of autofluorescence from the block of plastic that is the base material for a chip, another once the block has been fashioned into the substrate in which the functional components are embedded, and yet another as the final device is completed,” Stavis says.
“To manufacture lab on a chip devices with reliably low autofluorescence, accurate measurements may be needed at each stage.”
