Sustainability matters : polylactic acid, a natural origin polyester for the rapid prototyping of microfluidic devices. From point-of-care to organ-on-chip applications

Abstract

The nature of the material to be employed is one of the first factors manufacturers must take into account when embarking upon the design and production of a new microfluidic device. Silicon and glass have traditionally been used for manufacturing micro-features but polymeric materials, including thermoplastics, have recently been explored. The required microfluidic functions, degree of integration and application are the principal issues that must be considered when choosing a material. However, environmental sustainability is another concern that is of increasing importance due to the dramatic rise in the amount of medical plastic waste produced globally, largely driven by the use of single-use, disposable medical equipment. The advent of point-of-care diagnostics, in labon-chip format, is likely to add further to the amount of healthcare waste generated and, therefore, embedding sustainability at the research stage is essential. This thesis describes the possibility of making research prototypes and future products more sustainable across their entire lifecycle, from raw material to the finished article, by proposing the use of chemically recycled and natural origin polymers. First, a safe and cost effective protocol to bond conventional polymethyl metacrylate, PMMA, based microfluidic devices is investigated and the possibility to use chemically recycled PMMA taken into consideration. Polylactic acid, PLA, is introduced as environmentally sustainable solution and the CO2 laser cut workability improved to microstructure microfluidic devices. PLA material properties are investigated to assess material suitability for point-of-care and microfluidic cell culture applications.