Fabrication of Biomaterial-Based Triboelectric Nanogenerators: Study of the Relationship between Output Performance and Strain in Dielectric Materials

Abstract

A triboelectric nanogenerator (TENG) collects thriftless mechanical energy from the surrounding environment and transforms it into electrical energy. This work demonstrated a feasible method for metallizing the polylactic acid (PLA) surface, which was subsequently used as a biomaterial-based TENG electrode material. We demonstrated that microcellular holes and hydrophilic groups (−C-OH and −COOH) were introduced on an alkali-treated PLA sheet surface, subsequently used to absorb Pd 2+ by means of covalent bonds, which could serve as catalytic centers for the reduction of Ni 2+ . Of note, the Ni-layer deposition mechanism represents a typical island-like growth pattern. To be precise, a Ni-coated PLA sheet was fabricated successfully and used as a TENG electrode material. The device had excellent performances, with a maximum output voltage of about 5.1 V, obtained from 6% strain (the corresponding stress is 32.4 kPa) on the PDMS layer. Furthermore, it revealed that under a stress of 0.14−32.4 kPa and strain of 1.3−6%, a linear regression relation existed between the output voltage and the dielectric material strain, and it was found that the density of electrostatic charge formed on the TENG material surface is 4.1 × 10 6 C/m 2 . Additionally, the as-fabricated TENG equipment was attached to various positions of the human body and lab to demonstrate the electrical energy obtained from the mechanical movement. It was also used for real-time demonstrations as a self-powered body-tracking device application which may be beneficial in tracking human position counters during self-powered and emergency exercise movements.

Electroless Copper Plating on a Cotton Surface: Effect of Metal Ion Ligand Stability Constant on Reduction Deposition

“…The outermost electrons of O and Ag + exhibit 2s 2 2p 4 and 4d 10 hybrid orbitals (Figure c II and III), respectively. According to hybrid orbital theory, sp 3 hybrids have lone pairs of electrons, and more importantly, due to ionic coordination behavior, lone pairs of electrons in O hybrid orbitals tend to occupy Ag + (sp hybridization, as displayed in Figure c II). ,, This allows a strong force to be established between the active group and the metal ion, manifested as a coordination bond (Ag–O). More importantly, such coordination bonds can also be established between the copper and oxygen particles.…”

“…Traditional electroless copper plating with formaldehyde as a reducing agent is gradually replaced by sodium hypophosphite as a reducing agent . However, since copper has no catalytic effect on the oxidation of sodium hypophosphite, it is necessary to add nickel ions or diamond ions as catalysts. − At present, sodium hypophosphite electroless copper plating systems mostly use trisodium citrate as the coordination agent, and the copper film deposited in this system is dark red, presenting high nickel, phosphorus content, and high resistivity, which is not good for practical applications . This is because sodium citrate is used as the complexing agent in the plating bath, and the stability constant of the citrate-Cu(II) complex is much higher than that of the citrate-Ni(II) stability constant (14.2/5.4), making Ni(II) more easily deposited, resulting in higher Ni and P contents at the beginning of deposition, which not only affects the conductivity of the coating but also affects the conductivity of the coating.…”