Piezoelectric Properties of Plant Derived Crystalline Nano Cellulose Composites

Cellulose is the most common biopolymer on earth, it is found in the wall of all plant cells and is easily produces from wood and cotton. Recently, the properties of plant derived materials such as cellulose are further explored, revealing amazing and useful properties. using modern technology, we can modify and enhance the properties of these biomaterials to be used even in unexpected fields, such as electronic devices.

Cellulose fibers are comprised of amorphous and crystalline regions, which can be isolated by acid hydrolysis. The resulting rigid crystalline particles are known as cellulose nanocrystals (CNC). The suspensions can be cast and evaporated, leaving a thin, transparent, flexible film. Due to the crystalline nature of the particles, CNC films can exhibit piezoelectric properties.

The hypothesis for this research poses that treating CNC films with various electrical and chemical treatments as well as incorporation of different particles in the CNC suspension may increase the piezoelectric voltage output of the films. These treatments include electric field poling, or chemical crosslinking, using a poly-carboxylic acid. Another approach is the synthesis of magnetic nanoparticles on the surface of the CNC particles and subsequent drying under magnetic fields to better align the crystalline particles in order to increase the charge separation.

Different treatments show an increase in the average voltage output measured under applied force. Increasing the voltage output of CNC films may be the basis for developing a plant based, cheap, and degradable material for energy harvesting, motion and touch sensing thin transparent films.