Mitigating broadband noise with passive airborne sound absorbers has been a long-lasting challenge, particularly for low-frequency anthropogenic sounds below kilohertz with long wavelengths, which require bulky materials for effective absorption. Here, we propose a strategy that utilizes local triboelectric effect and in-situ electrical energy dissipation mechanism for airborne sound absorption. This approach involves a fundamentally different mechanism that converts airborne sound into electricity for energy dissipation, in contrast to conventional mechano-thermal energy conversion mechanisms. We establish an equivalent acoustic impedance model to provide theoretical analysis of the underlying sound absorption mechanisms, with a theoretical maximum mechano-electro-thermal coupling efficiency approaching 100% under optimal conditions. We design fibrous triboelectric composite foam materials accordingly and show their substantially boosted acoustic absorption performance experimentally, where the adoption of diverse triboelectric material pairs validates that a larger difference in material charge affinities intensifies the local triboelectric effect and results in higher acoustic absorbing performance. A strategy for effective broadband sound absorption by utilizing local triboelectric and electrical energy dissipation mechanisms is proposed and demonstrated with composites comprising paired materials with large electrical affinity difference.

When testing the output of piezoelectric devices under different pressures, the friction between the pressure platform and the device causes a large amount of frictional electrical signals to be mixed in the output piezoelectric signal, seriously affecting the measurement accuracy of the piezoelectric signal. The current solution is to encapsulate the contact interface with identical materials to suppress triboelectric interference. However, this work has shown that even when contact separation is implemented at the interface of same media, triboelectric signals can still be generated. The heterogeneous potential distribution of the same material in contact separation has been discovered for the first time through the contact interface potential distribution, proving that charge transfer still exists between the same materials. Atomic force microscopy (AFM) was used to analyze the microstructure of the interface, and it was found that the existence of the surface tip structure would enhance the electron loss. Based on this, a new electron transfer model for surface–tip electron cloud interaction is proposed in this work. In addition, by comparing the output voltage characteristics of the triboelectric nanogenerators (TENGs) of seven polymer materials (e.g., polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), polyoxymethylene (POM), polyimide (PI), and polyethylene terephthalate (PET)), it was found that the open circuit voltage of PP material was only 0.06 V when they friction with each other, which is 2–3 orders of magnitude lower than other materials. When PP materials are applied to the package of piezoelectric devices, the precision of piezoelectric output characterization can be improved significantly, and a new experimental basis for a triboelectric theory system can be provided.

the triboelectric effect and results in one material becoming positively charged and the other negatively charged. The triboelectric effect is the main Static electricity is an imbalance of electric charges within or on the surface of a material. The charge remains until it can move away as an electric current or by electrical discharge. The word "static" is used to differentiate it from current electricity, where an electric charge flows through an electrical conductor. A static electric charge can be created whenever two surfaces contact and/or Electrons or ions can be exchanged between materials on contact or when they slide against each other, which is known as the triboelectric effect and results in one material becoming positively charged and the other negatively charged. The triboelectric effect is the main cause of static electricity as observed in everyday life, and in common high-school science demonstrations involving rubbing different materials together (e.g., fur against an acrylic rod). Contact-induced charge separation causes one's hair to stand up and causes "static cling" (for example, a balloon rubbed against the hair becomes negatively charged; when near a wall, the charged balloon is attracted to positively charged particles in the wall, and can "cling" to it, suspended against gravity). A charged object brought close to an electrically neutral conductive object causes a separation of charge within the neutral object. This is called electrostatic induction. Charges of the same polarity are repelled and move to the side of the object away from the external charge, and charges of the opposite polarity are attracted and move to the side facing the charge. As the force due to the interaction of electric charges falls off rapidly with increasing distance, the effect of the closer (opposite polarity) charges is greater and the two objects feel a force of attraction. Careful grounding of part of an object can permanently add or remove electrons, leaving the object with a global, permanent charge.