MICRO MOULDING | ARTICLE
What is a lab-on-a-chip demonstrator? Developments in micro fluidics allow for chemical analyses to be performed with an unprecedented speed on a thumbnail-sized plastic substrate, that is known as a lab-on-a-chip. Thus, new tools are available, not only for classical chemistry, but also for medical diagnostics. Micro fluidic channels, analogous to the conductor strips in micro electronics, are the central components of such a vest-pocket lab. The channels, no thicker than a hair, are required for transporting, mixing and separating reagents down to a pico litre scale. In practice such labs are used for performing HIV tests or for blood inflammatory markers, among other applications.
In order to show such a production scenario, MSV and Wittmann Battenfeld GmbH joined in a project and designed a multistage 2-component injection moulding and assembly process that was demonstrated at the K trade show in October last year. The manufacturing cell consists of two micro injection moulding machines connected together via a cleanroom tunnel through which the moulded parts are conveyed from the first machine to the second.
In the first injection moulding machine a 1+1-cavity family mould produces the two main components of the lab-on-a-chip: the base plate with the micro structures and a top part (housing).
In the base plate the 300 µm micro channels and chambers with static micro mixing features are moulded, and so is an optical lens. The function of this lens is to permit the automatic checking of fluidic reaction results, for example with the use of a camera.
The top part is characterised by three LUER cones. Two of these connections are used to feed the liquids — one sample liquid and one reagent — to the system. Via the third LUER cone the flow rate is controlled by applying vacuum in order to reinforce the capillary effect.
After moulding the two parts are transported by an in-the-cell integrated scara robot to a camera check in order to be tested for dimensional stability, absence of flashes and optical purity. Afterwards the scara assembles the two parts and places the assembly on a shuttle module for the transport to the second moulding machine via a cleanroom tunnel. Here a similar scara handling system picks up the minilab and places it in a single- cavity mould where it is overmoulded with TPE. With this a gasket between the micro plate and cover is formed, as well as a handle element.
>> Continued on page 10
<< Figure 2: Micro Systems
Vienna production area. >>
9| commercial micro manufacturing international Vol 7 No.4
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52