Analysis of the cellular response to piezoelectric materials has been driven by the discovery that many tissue components exhibit piezoelectric behavior ex vivo. In particular, polyvinylidene fluoride and the trifluoroethylene co-polymer (PVDF-TrFE) have been identified as promising piezo and ferroelectric materials with applications in energy harvesting and biosensor devices. Critically, the modulation of the structural and crystalline properties of PVDF-TrFE through annealing processes and the addition of particulate or fibrous fillers has been shown to modulate significantly the materials electromechanical properties. In this study, a PVDF-TrFE/boron-nitride nanotube composite was evaluated by modulated differential scanning calorimetry to assess the effects of boron nitride nanotube addition and thermal annealing on the composite structure and crystal behavior. An increased beta crystal formation [f(β) = 0.71] was observed following PVDF-TrFE annealing at the first crystallization temperature of 120°C. In addition, the inclusion of boron nitride nanotubes significantly increased the crystal formation behavior [f(β) = 0.76] and the mechanical properties of the material. Finally, it was observed that BNNT incorporation enhance the adherence and proliferation of human tenocyte cells in vitro.

There is an unmet clinical need to provide viable bone grafts for clinical use. Autologous bone, one of the most commonly transplanted tissues, is often used but is associated with donor site morbidity. Tissue engineering strategies to differentiate an autologous cell source, such as mesenchymal stromal cells (MSCs), into a potential bone-graft material could help to fulfill clinical demand. However, osteogenesis of MSCs can typically require long culture periods that are impractical in a clinical setting and can lead to significant cost. Investigation into strategies that optimize cell production is essential. Here, we use the piezoelectric copolymer poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE), functionalized with a poly(ethyl acrylate) (PEA) coating that drives fibronectin network formation, to enhance MSC adhesion and to present growth factors in the solid phase. Dynamic electrical cues are then incorporated, via a nanovibrational bioreactor, and the MSC response to electromechanical stimulation is investigated.

Dielectric nanocomposite elastomers based on poly(styrene-ethylene/butylene-styrene) (SEBS) and SEBS-grafted-maleic anhydride (SEBS-g-MA) with barium titanate (BT) suitable for electroactive applications were successfully manufactured by using two corotating twin extrusion systems. The main purpose of the work was to investigate the thermal, mechanical, dielectric, and morphological effects of additives on SEBS and SEBS-g-MA to widen their applications for electroactive applications using fast and more cost-effective simple production process. The morphological characterization showed a good and bad dispersion of BT into SEBS-g-MA and SEBS with 34.9% and −3% dielectric permittivity change in SEBS-g-MA and SEBS upon addition of 10 wt% BT. In addition, dielectric permittivity change, thermal change (enthalpy relaxation and thermal transitions), and mechanical (Young’s modulus, hysteresis loss under multiple stress cycles, storage modulus, loss modulus, and tan δ) properties of elastomers were found to be a function of additive concentration, compatibility and interaction between elastomers and additive type, orientation of additives, and reinforcing factors of additives in elastomers. A simple and effective modeling technique was used to demonstrate the effects of dielectric properties on nanocomposites due to poor dispersion of additives.