M.S. Mechanical Engineering
Henry M. Rowan College of Engineering
carbon nanotubes, piezoelectric, piezoresistive, polydimethysiloxane, porous, zinc oxide
Biosensors; Composite materials
Materials Science and Engineering | Mechanical Engineering
In this paper, polydimethylsiloxane (PDMS), carbon nanotubes (CNTs), and zinc oxide (ZnO) were combined to create functionalized piezoresistive and piezoelectric sensors for pressure sensing and energy harvesting. Samples were foamed to show that the increased deformability of the foam sensors makes them suitable for a range of applications including dexterous robotics, tactile sensing, energy harvesting, and biosensing. Uniform dispersion of CNTs was achieved with chloroform as the solvent. Samples were foamed using chemical blowing and scaffolding but granulated sugar at 70% porosity resulted in foamed samples with the most consistent mechanical properties. Samples underwent tensile and compressive testing for their mechanical properties. These test's results showed that introducing pores did not significantly degrade sensor performance. Porous devices are more ductile and use less materials than their bulk counterparts. Piezoresistive sensors with 3.5% CNTs yielded the highest sensitivity with a Young's modulus of 0.42 MPa. To further functionalize the devices, ZnO is mixed into the samples to produce piezoelectric devices. Dipole alignment is done in an attempt to increase the output power of piezoelectric devices. This resulted in a 5x increase in performance of the devices and further research needs to be conducted. Overall, porous PDMS functions for both piezoelectric and piezoresistive device applications.
Michel, Taissa Rose, "Functional porous polydimethlysiloxane as piezoresistive and piezoelectric materials" (2019). Theses and Dissertations. 2698.