ABSTRACT
Particulate matter (PM) in the environment can adversely affect the health of living things. However, high removal efficiency and low-pressure loss are crucial design challenges for any air filtration system. To circumvent the challenge, here, we demonstrate a novel triboelectric (TE) air filtration system that is based on a rotation-type triboelectric nanogenerator (TENG) and a filter comprising two sets of plates: primary and secondary, that are placed in the airflow channel. When the TENG charges the two plate sets with opposite charges, the flowing air particles are charged at the primary plates and are collected, due to an electric field, at the secondary plates. The TE filter has demonstrated a PM2.5 removal efficiency of ~ 99.97% for the fine dust particles, and it remains stable even after several washing cycles. The pressure loss is almost two orders less than the high-efficiency particulate air filter. Since the airflow itself can drive the TENG, the TE filter can potentially be integrated with any air conditioning system for fine dust filtration in offices, automobiles, etc.
ABSTRACT
Effective mitigation technology to prevent the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is required before achieving population immunity through vaccines. Here we demonstrate a virus-blocking textile (VBT) that repulses SARS-CoV-2 by applying repulsive Coulomb force to respiratory particles, powered by human body triboelectric energy harvesting. We show that SARS-CoV-2 has negative charges, and a human body generates high output current of which peak-to-peak value reaches 259.6 µA at most, based on triboelectric effect. Thereby, the human body can sustainably power a VBT to have negative electrical potential, and the VBT highly blocks SARS-CoV-2 by repulsion. In an acrylic chamber study, we found that the VBT blocks SARS-CoV-2 by 99.95%, and SARS-CoV-2 in the VBT is 13-fold reduced. Our work provides technology that may prevent the spread of virus based on repulsive Coulomb force and triboelectric energy harvesting.
ABSTRACT
In recent years, smart light-emitting-type electronic devices for wearable applications have been required to have flexibility and miniaturization, which limits the use of conventional bulk batteries. Therefore, it is important to develop a self-powered light-emitting system. Our study demonstrates the potential of a new self-powered luminescent textile system that emits light driven by random motions. The device is a ZnS:Cu-based textile motion-driven electroluminescent device (TDEL) fabricated onto the woven fibers of a ZnS:Cu-embedded PDMS (polydimethylsiloxane) composite. Triboelectrification, which raises a discontinuous electric field, is generated by the contact separation movement of the friction material. Therefore, light can be generated via triboelectrification by the mechanical deformation of the ZnS:Cu-embedded PDMS composite. This study showed that the TDEL emitted light from the internal triboelectric field during contact and from the external triboelectric field during separation. Light was then emitted twice in a cycle, suggesting that continuous light can be emitted by various movements, which is a key step in developing self-powered systems for wearable applications. Therefore, this technology is a textile motion-driven electroluminescence system based on composite fibers (ZnS:Cu + PDMS) and PTFE fibers, and the proposed self-emitting textile system can be easily fabricated and applied to smart clothes.
