In this research, natural rubber (NR)-TiO₂ nanocomposites were developed for triboelectric nanogenerator (TENG) application to harvest mechanical energy into electrical energy. Rutile TiO₂ nanoparticles were used as fillers in NR material to improve dielectric properties so as to enhance the energy conversion performance of the NR composite TENG. The effect of filler concentration on TENG performance of the NR-TiO₂ composites was investigated. In addition, ball-milling method was employed to reduce the agglomeration of TiO₂ nanoparticles in order to improve their dispersion in the NR film. It was found that the TENG performance was significantly enhanced due to the increased dielectric constant of the NR-TiO₂ composite films fabricated from the ball-milled TiO₂. The TENG, fabricated from the NR-TiO₂ composite using 24 h ball-milled TiO₂ at 0.5%wt, delivered the highest power density of 237 mW/m², which was almost four times higher than that of pristine NR TENG. Furthermore, the applications of the fabricated NR-TiO₂ TENG as a power source to operate portable electronics devices were also demonstrated.

The COVID-19 pandemic emphasized the importance of rapid, portable, and on-site testing technologies necessary for resource-limited settings for effective testing and screening to reduce spreading of the infection. Realizing this, we developed a fluorescence-based point-of-care (fPOC) detection system with real-time reverse transcriptase loop-mediated isothermal amplification for rapid and quantitative detection of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. The system is built based on the Arduino platform compatible with commercially available open-source hardware–software and off-the-shelf electronic components. The fPOC system comprises of three main components: 1) an instrument with integrated heaters, 2) optical detection components, and 3) an injection-molded polymeric cartridge. The system was tested and experimentally proved to be able to use for fast detection of the SARS-CoV-2 virus in real-time in less than 30 min. Preliminary results of testing the performance of the fPOC revealed that the fPOC could detect the SARS-CoV-2 virus at a limit of detection (LOD_50%) at two to three copies/microliter (15.36 copies/reaction), which was comparable to reactions run on a standard commercial thermocycler. The performance of the fPOC was evaluated with 12 SARS-CoV-2 clinical throat swab samples that included seven positive and five negative samples, as confirmed by reverse transcription–polymerase chain reaction. The fPOC showed 100% agreement with the commercial thermocycler. This simple design of the fPOC system demonstrates the potential to greatly enhance the practical applicability to develop a totally integrated point-of-care system for rapid on-site screening of the SARS-CoV-2 virus in the management of the pandemic.