Synergetic effect of multi-walled carbon nanotubes (MWCNTs)/nanoclays hybrid was investigated on the properties of highimpact polystyrene (HIPS) nanocomposite foams. The glass transition temperature and the cellular structure including the cell size and cell density were studied in details. Adding MWCNT and nanoclay increased the glass transition temperature of HIPS by 8.5 °C and 1.5 °C, respectively. The experimental results indicated that the cell size of HIPS foams was reduced from 84.05 to 60.97 μm and 40.22 μm using MWCNTs and nanoclays, respectively. The synergetic effect of MWCNT/nanoclay was more significant by reducing the cell size to 13.69 μm. The cell density was improved from 5.79 × 104 to 1.77 × 105 cell/ cm3 using MWCNTs and to 9.39 × 106 cell/cm3 using nanoclays. The cell density reached to 2.90 × 107 cell/cm3 using the synergetic effect of MWCNT/nanoclay.

A flexible piezoelectric energy harvester(f-PEH) that converts tiny mechanical and vibrational energy resources into electric signals without any restraints is drawing attention as a self-powered source to operate flexible electronic systems. In particular, the nanocomposites-based f-PEHs fabricated by a simple and low-cost spin-coating method show a mechanically stable and high output performance compared to only piezoelectric polymers or perovskite thin films. Here, the non-piezoelectric polymer matrix of the nanocomposite-based f-PEH is replaced by a P(VDF-TrFE) piezoelectric polymer to improve the output performance generated from the f-PEH. The piezoelectric hybrid nanocomposite is produced by distributing the perovskite PZT nanoparticles inside the piezoelectric elastomer; subsequently, the piezoelectric hybrid material is spin-coated onto a thin metal substrate to achieve a nanocomposite-based f-PEH. A fabricated energy device after a two-step poling process shows a maximum output voltage of 9.4 V and a current of 160 nA under repeated mechanical bending. Finite element analysis(FEA) simulation results support the experimental results.