Temperature control in miniaturised devices for fast medical diagnostics

Sirris and MEDVIA are working together on Medical Diagnostics Goes Micro and Smart, a Vlaio-funded research-to-industry tech transfer project. Sirris has produced a series of articles on microfluidics to help industry better understand what it can provide to them.

ARTICLE 7 of 7

In this article of our series on microfluidic lab-on-chips, we describe how to apply and control the temperature in ‘miniaturised’ geometries, as is the case for microfluidic chips. Are you a designer or engineer who needs to realise strict temperature control – heating as well as cooling – within small dimensions? Here we tell you more about using thermo-electric modules.

PCR testing

There are many reasons why the sample fluid in a lab-on-a-chip must be brought to certain temperatures: to destroy contaminants, activate reagents, start or stop chemical reactions, etc. This is especially the case for PCR cycling (polymerase chain reaction), in which – simply said – a marked fraction of DNA or RNA is replicated multiple times, and the amount of ‘DNA of interest’ is doubled each cycle. A PCR cycle consists of three steps (denaturation, annealing, extension), each of which occurs at a specific temperature (resp. 95, 55 and 72 °C), to be applied with a tolerance of better than ±1° or even ±0.5°.

Nowadays, laboratory equipment is used in which a container holding tens to even hundreds of samples (each about 1 or a few ml in size; 1 ml = 1 cc = 1000 mm3), is thermally cycled. In addition to the time it takes to get the samples in the lab, prepare them and load them in the containers, also the limited temperature change rate and required hold time to assure correct temperature at each step throughout all samples, makes these tests take a long time to execute.

Read the rest of the article here

 

Article 1: Microfluidics – how an entire lab process fits on a bank card
https://www.sirris.be/en/inspiration/microfluidics-how-entire-lab-process-fits-bank-card

Article 2: Microfluidic chip design
https://www.sirris.be/en/inspiration/microfluidic-chip-design

Article 3: Manufacturing and prototyping techniques for polymer-based microfluidic chips
https://www.sirris.be/en/inspiration/manufacturing-and-prototyping-techniques-polymer-based-microfluidic-chips-brief

Article 4: Computer vision used for detection of fluid front in microfluidic chip
https://www.sirris.be/en/inspiration/computer-vision-used-detection-fluid-front-microfluidic-chip-part-4

Article 5: Closing event of project Medical Diagnostics Goes Micro and Smart
https://www.sirris.be/en/inspiratie/slotevent-project-medical-diagnostics-goes-micro-and-smart

Article 6: Lab-a-chip detection techniques
https://www.sirris.be/en/inspiration/lab-chip-detection-techniques-part-6