This week (31 Oct – 6 Nov) is #RealTimeChem Week – if you’re a tweeting chemist or chemistry enthusiast, you’ll probably know what that is already, but if you’re not familiar with it check out the FAQ here! Like last year, I’m creating graphics showcasing the work of the three winners of the #RealTimeChem week competition I ran earlier in October – hopefully explaining cutting edge research in easily understandable terms!
Today’s graphic takes a look at the research of Sarah Hampson (@sarahmhamps), a PhD student from Loughborough University who’s currently investigating 3D printed lab-on-a-chip devices and their potential to be used for disease diagnosis or particle analyser chips. Here’s Sarah to tell us more:
“A lab-on-a-chip (LOC) is a small, handheld device that carries out tasks usually needing a laboratory (such as chemical analysis). Two well-known examples are blood glucose tests used by diabetics, and home pregnancy tests. However, despite a whole host of other applications of LOCs in both health and environmental monitoring, these two examples remain the only true success stories of the field. This is because current LOC design is time-consuming and restrictive: nearly all LOCs today are made by carefully forming individual layers of PDMS (polydimethylsiloxane) and bonding them altogether.
One alternative is 3D printing. This process involves the computer-controlled transformation of data into a 3D, physical object. In the last decade it has grown from being a specialist technique to one almost universally recognised, and as of 2016, the 3D printing industry has now surpassed $5.1 billion. It has led to much innovation across many fields, including Chemistry, due to its unique design freedom, speed, material variety, and digital, easy-to-use file format. ‘3D printing’ is actually an umbrella term- there are many different types of 3D printing.
My work involves developing LOCs using 3D printing. More and more lab-on-a-chip chemists are now using 3D printing to design their LOCs- there’s been quite a few ones printed recently that do chemical synthesis, for example. My particular area is making LOCs that can analyse particles and cells.
I use one type of 3D printing called stereolithography to make my LOCs, because it’s particularly good at printing fine detail. It involves using a very fine laser to draw out your part layer-by-layer in a bath of resin. As the laser moves, it causes a chemical reaction called a photopolymerisation that solidifies the resin goo into your part. The resin contains liquid monomers (usually acrylates) and a photoiniatiator that releases either cations or free radicals when exposed to light (such as sulfonium salts or benzoin ether derivatives respectively). These cations and free radicals react with the monomers and cross-link them into a large, solid polymer network.
3D printing allows me to make lab-on-a-chip devices very cheaply and quickly- the chips I am developing take only a few hours and cost less than $12 to print, and they’re printed complete, in one go (in comparison to having to make layers, as with PDMS).
My particle and cell analyser chips have two main applications. The particle analyser chips could be used in nanotechnology research, to do quality control of particle synthesis, whilst the cell analyser chips could be integrated into LOCs for disease diagnosis. These disease diagnosis chips could be made cheaply and posted out to people in areas hit by epidemics of infectious diseases.”