Researchers at the Massachusetts Institute of Technology (MIT) have achieved a groundbreaking advancement in disease detection by leveraging 3D printing to create self-heating microfluidic devices. These miniature devices, manipulating fluids and facilitating chemical reactions, could pave the way for cost-effective and precise tools to detect various diseases.
Even though there are microfluidic applications – such as COVID-19 test kits for use at home – complex devices frequently need particular temperature settings. The traditional production process uses expensive materials like gold or platinum for the heating elements, and it entails complex cleanroom procedures. The innovation from MIT provides an alternative.
Using 3D Printing for Disease Detection Tools
The MIT team utilized multi-material 3D printing to produce self-heating microfluidic devices in a single, affordable manufacturing step. They created an electrical conductor out of a biodegradable polymer (PLA) by mixing it with a modified version that contained copper nanoparticles. This resulted in the creation of a heating element for the fluid inside of microscopic channels.
This novel method has the potential to democratize diagnostic technology by enabling those living in isolated areas with limited access to pricey lab equipment to use it. For the low-cost fabrication method to produce a microfluidic that is ready for usage, roughly $2 worth of materials are needed. Luis Fernando Velásquez-García, a principal scientist and the lead researcher at MIT, emphasizes that this approach can produce capable self-heating microfluidic devices faster and cheaper than traditional methods.
“Clean rooms in particular, where you would usually make these devices, are incredibly expensive to build and to run. But we can make very capable self-heating microfluidic devices using additive manufacturing, and they can be made a lot faster and cheaper than with these traditional methods. This is really a way to democratize this technology, says Luis Fernando Velásquez-García.”
Creating Self-heating Microfluidics with PLA
The researchers employed two materials to build self-heating microfluidics: a modified version of polylactic acid (PLA), a biodegradable polymer. By incorporating copper nanoparticles into the polymer, the modified PLA changes from an insulator to an electrical conductor. This copper-doped PLA resistor dissipates energy as heat when an electrical current is applied to it.
The resulting device, roughly the size of a U.S. quarter, can heat fluid by 4 degrees Celsius in just minutes. The PLA material’s translucency allows for visualization during chemical reactions, which is crucial for many diagnostic processes. The researchers successfully demonstrated the capability to create prototypes with customizable heating profiles and gradients.
“It is amazing when you think about it because the PLA material is a dielectric, but when you put in these nanoparticle impurities, it completely changes the physical properties. This is something we don’t fully understand yet, but it happens and it is repeatable, says Velásquez-García.”
The proposed monolithic 3D-printed microfluidic systems have garnered attention globally. Professor Norihisa Miki from Keio University sees beauty in simplicity, highlighting the potential for diverse applications. Likewise, Niclas Roxhed from KTH Royal Institute of Technology envisions applications such as amplifying biomarkers or implantable devices that dissolve over time.
“In Japanese culture, it’s often said that beauty lies in simplicity. This sentiment is echoed by the work of Cañada and Velasquez-Garcia. Their proposed monolithically 3D-printed microfluidic systems embody simplicity and beauty, offering a wide array of potential derivations and applications that we foresee in the future, said Norihisa Miki.”
