Lab-on-a-chip products that are made with micro and nanotechology offer a challenge in quality control. Micronit distinguishes three types of quality parameters geometrical, functional and cosmetic. A very important tool in in Quality Control is Statistica Process Control.
Statistical Process Control
Statistical Process Control (SPC) is a method of quality control which uses statistical methods. Statistical Process Control for lab-on-a-chip products at Micronit is applied in order to monitor and control the lab-on-a-chip manufacturing processes. Using Statistical Process Control allows Micronit to make as much conforming product as possible with a minimum of waste. Micronit uses Statistical Process Control analytical tools such as MiniTab to analyze data collected during manufacturing. The use of control charts with a focus on continuous improvement and the use of design of experiments allow Micronit to manufacture high quality devices in a cost effective way. Monitoring our processes allows us to determine the level of confidence level we want for the product and as a result determine the tolerance window that is possible for such a confidence level. Or we can determine the confidence level based on specifications requirements determined by an end application required accuracy.
The geometrical parameters can be measured with adequate measurement tools. These can be quantified like for instance channel depth, width, length, etc. Micronit uses several tools connected to our Quality database. In this database measurement data is recorded in order to judge the conformance of the product with the requirements. The measurement protocols have been standardized and the data is analyzed with statistical tools.
Functional quality control refers to quality measurement that are focused on identifying defects that are related to the functionality of the product but not always easily measureable but most of the time quantifiable. These defects could be for instance local channel deformation due to manufacturing issues or the measurement of flow resistance of a microfluidics device. Micronit builds on a long history of implementing similar procedures for other products.
Cosmetic Quality control focusses on the parameters that are importance of the quality perception of the product by the end user of the product. There is no direct relation between proper functioning of the device and these quality parameters. The quality measurements are most of the time related to visual appearance of the device. Proper barcoding, the right color of a logo, no visual defects or discoloration and many more.
Lab-on-a-chip quality control measurements
Feature sizes in lab on chip devices start from tens of nanometers up to millimeters in size. One of the challenges is the absolute accuracy of the measurements for smaller features sizes. Accurate measurement of channel dimensions is very important for the performance of the devices. For instance in the case of shallow microfluidic channels the fluidic resistance of a microfluidic structure relates to the depth to third power. This means that 1% of channel depth variation translates is about 3% variation in channel fluidic resistance. The above stresses the importance of very accurate and reproducible measurements. Micronit uses Measuring System Analysis methods that usesstandards and controls and regular calibration to ensure the quality of products delivered.
In order to guarantee the quality of products and services the Micronit team is dedicated to implementing the right quality control procedures to secure the quality of the products manufactured by Micronit.