Fabrication of piezoelectric poly(L-lactic acid)/BaTiO3 fibre by the melt-spinning process.

Poly(L-lactic acid) (PLLA) based piezoelectric polymers are gradually becoming the substitute for the conventional piezoelectric ceramic and polymeric materials due to their low cost and biodegradable, non-toxic, piezoelectric and non-pyroelectric nature. To improve the piezoelectric properties of melt-spun poly(L-lactic acid) (PLLA)/BaTiO3, we optimized the post-processing conditions to increase the proportion of the ß crystalline phase. The α → ß phase transition behaviour was determined by two-dimensional wide-angle x-ray diffraction and differential scanning calorimetry. The piezoelectric properties of PLLA/BaTiO3 fibres were characterised in their yarn and textile form through a tapping method. From these results, we confirmed that the crystalline phase transition of PLLA/BaTiO3 fibres was significantly enhanced under the optimised post-processing conditions at a draw ratio of 3 and temperature of 120 °C during the melt-spinning process. The results indicated that PLLA/BaTiO3 fibres could be a one of the material for organic-based piezoelectric sensors for application in textile-based wearable piezoelectric devices.

Triboelectric touch sensor for position mapping during total hip arthroplasty.

OBJECTIVE: In this research, a triboelectric nanogenerator (TENG) was utilized to determine if a pressure-based sensor could detect bearing friction in a total hip arthroplasty (THA) and detect the contact of specific areas during ROM checks. RESULTS: The pressure-based sensor shows capability to sense bearing friction. In more detail, the TENG embedded in four different sides of the trial exhibits up to 1 V from peak-to-peak. Moreover, these flexible touch sensors with TENG describes a peak signal in output voltage which should lead to extremely sensitive detection of bearing friction induced by the THA.

Improved Output Voltage of a Nanogenerator with 3D Fabric.

Electrically enhanced triboelectric nanogenerators (TENGs) using 3D fabrics and polydimethylsiloxane (PDMS) are suggested for next-generation wearable electronics. TENGs with fabric-fabric- fabric (FFF) and PDMS-fabric-PDMS (PFP) structures were fabricated with ordinary 2D fabrics and honeycomb-like 3D fabrics. A 3D fabric TENG with an FFF structure showed an output voltage of 7 V, 7 times higher than a 2D fabric FFF structured TENG. Interestingly, an extremely high output voltage of 240 V was achieved by a 3D fabric PFP structured TENG. This was attributed to the high surface frictional triboelectric effect between fabric and PDMS and also marginal 3D structure in the 3D fabric active layer.

Synthesis and Charge Transport of Polymer Nanocomposite of Polyaniline: Polystyrene Sulfonate.

We demonstrate the preparation of water-dispersible polyaniline:polystyrene sulfonate (PANI:PSS), which was doped with camphorsulfonic acid (CSA) and co-doped with poly (4-styrenesulfonic acid) (PSS). The proper formation of the PANI and PANI:PSS was verified by FTIR measurements. The synthesized samples were further characterized via UV-vis spectroscopy. The intensive study on the current density (J)-voltage (V) characteristics within the temperature range (143-303 K) of the synthesized sample was performed systematically. The electrical study shows that the doping of PANI with CSA as a dopant and PSS as a co-dopant significantly improves the overall semi-conducting property of PANI. The detailed analysis of the current density (J)-voltage (V) curve at various temperatures reveals the electrical conduction behavior, which follows the trap-dependent space-charge limited conduction (SCLC) mechanism.