An overview of polylactic acid (PLA) nanocomposites for sensors

Polylactic acid (PLA) nanocomposites are lightweight, environmentally friendly, easy fabrication, low cost, and excellent biocompatibility. Its nanocomposites are usually made of PLA matrix filled with nano-fillers such as nanotubes (e.g., carbon nanotubes), quantum dots, nanoclays, nanofibers, graphene, and even other polymers. Compared to PLA, PLA nanocomposites can have improved electrical properties, higher thermal conductivity, dielectric constant, better thermal stability, biodegradability, and so on. Thus, PLA nanocomposites have been widely used for various sensing applications. This review discusses the common methods, such as chemical/physical modification and electrospinning, used to prepare the PLA nanocomposites. Meanwhile, recent applications of PLA nanocomposites as sensors in the field of moisture, piezo/strain, chemical/bio, thermal, and other fields are summarized in this review. The performances of each type of sensors have been highlighted in each section.