Expired Pharmaceutical Drugs as Tribopositive Material for Triboelectric Nanogenerator

The disposal of expired pharmaceutical drugs is largely unattended, which leads to massive environmental pollution. Herein, a novel strategy is demonstrated to turn expired drugs into a novel tribopositive material in a triboelectric nanogenerator (TENG). To realize the proposed method, three types of expired tablets such as paracetamol, nimesulide, and guaiphenesin are employed as tribopositive materials in TENG devices. Owing to their high electron donating capability with hydroxyl and carbonyl functional groups, these drugs reveal strong positive triboelectric potential. The proposed TENG devices yield open circuit voltages ranging from 267 to 561 V, while the short circuit current varies from 28 to 53 µA under a pneumatic air cylinder of 10 Hz. Impressively, the drug-based TENG can scavenge energy to light up to 169 commercial light-emitting diodes (LEDs). This excellent performance makes these expired drugs a promising positive tribomaterial, providing a possible solution to recycle a huge amount of pharmaceutical waste. These materials and reuse strategies are expected to aid the development of alternative sustainable energy conversion technology.</p

Snake ecdysis: A potential e-material for advanced electronic technology

Nature has gifted superior e-materials to many living organisms. This work investigates a keratinized hexagonal patterned snake ecdysis for advanced electronic applications. The snake ecdysis carries high porosity, flexibility, piezo-sensitivity, and tribopositivity. Furthermore, the presence of various functional groups and high keratinization are responsible for the piezo and triboelectric properties. First, we develop high-performance and impressively stable piezoelectric and triboelectric energy harvesters based on snake ecdysis. The snake ecdysis-based piezoelectric device is further utilized for various electronic applications such as speaker, microphone, and speech recognition sensor because of its outstanding wide band sensitivity. In addition, the snake ecdysis is further employed as a separator in a piezoelectric supercapacitor. The snake ecdysis/rGO-based piezoelectric supercapacitor delivers an excellent specific capacitance of 82 mF/cm2 with 72 mJ/cm2 energy density. These results suggest that snake ecdysis for energy harvesting, sensing, and storage applications could be an encouraging approach towards snake biodiversity as well as for developing sustainable self-driven electronic devices.</p

Triboelectric nanogenerator based on coastal bio-waste Ulva lactuca from Jeju island for sustainable energy harvesting

In the past, the occurrence of macro alga Ulva lactuca on the coastal areas of Jeju Island, Korea, has resulted in the expansion of devastating green tides, thus affecting coastal sustainability, aesthetic appearances, and tourism activities. Taking consideration of the above scenario, substantial economic costs are required for the environmental protection of the island, and it is highly recommended to employ Ulva lactuca in an alternative useful way. Hence, this paper proposes a new strategy to utilize Ulva lactuca as a tribopositive layer in a triboelectric nanogenerator (TENG). Based on the coastal bio-waste Ulva lactuca, the fabricated TENG device generates a maximum output voltage of 875 V, output current of 52 μA, and power density of 272.72 μW/cm2. Furthermore, the device presents excellent cyclic stability with no degradation in the output voltage even after 10000 consecutive cycles at a frequency of 2 Hz. The proposed TENG is further employed to charge the various commercially available capacitors, lightning LEDs, power stopwatches, and scavenge energy from body motions. It is anticipated that the proposed TENG device will pave a new way towards Ulva lactuca management for sustainable energy harvesting and clean coastlines

Ionic liquid multistate resistive switching characteristics in two terminal soft and flexible discrete channels for neuromorphic computing

By exploiting ion transport phenomena in a soft and flexible discrete channel, liquid material conductance can be controlled by using an electrical input signal, which results in analog neuromorphic behavior. This paper proposes an ionic liquid (IL) multistate resistive switching device capable of mimicking synapse analog behavior by using IL BMIM FeCL4 and H2O into the two ends of a discrete polydimethylsiloxane (PDMS) channel. The spike rate-dependent plasticity (SRDP) and spike-timing-dependent plasticity (STDP) behavior are highly stable by modulating the input signal. Furthermore, the discrete channel device presents highly durable performance under mechanical bending and stretching. Using the obtained parameters from the proposed ionic liquid-based synaptic device, convolutional neural network simulation runs to an image recognition task, reaching an accuracy of 84%. The bending test of a device opens a new gateway for the future of soft and flexible brain-inspired neuromorphic computing systems for various shaped artificial intelligence applications

Nature-Driven Edible Black Soldier Fly (BSF) Insect Larvae Derived Chitin Biofilm for Sustainable Multifunctional Energy Harvesting

With the increasing demand for portable electronic devices and the shortage of conventional energy resources, energy harvesting from natural resources has gained much attention. Herein, they proposed a black soldier fly (BSF) derived chitin biofilm to fabricate high-performance triboelectric and piezoelectric nanogenerators. The physiochemical characterizations of the chitin biofilm are demonstrated by the presence of the hydroxyl group, alpha chitin, and beta chitin, which are responsible for the remarkable tribopositive, and piezoelectric function of the chitin derived from BSF. The electrical performance of the proposed work, such as voltage, current, and instantaneous power from BSF/PTFE-based triboelectric nanogenerator (TENG) are exhibited at 121 V, 15 µA, and 217.8 µW, respectively. Ag/BSF/Ag piezoelectric nanogenerator (PENG) is generated 18 V voltage, 2.2 µA current, and 5 µW instantaneous power. Moreover, the proposed TENG and PENG devices demonstrate the ability to charge the dielectric capacitors and drive low-power electronic devices like LEDs and a calculator. The proposed results suggested that chitin is a superior biomaterial for developing sustainable energy harvesting devices.</p

Miniaturizing Power: Harnessing Micro-Supercapacitors for advanced micro-electronics

Rapid development in microelectronics demands the advancement of energy retention devices at the micro-scale, considering their compact size and remarkable ability to store energy. Due to high power density and speedy charge–discharge capacities, supercapacitors (SCs) have collected major attention as energy storage devices in the field of microelectronics. However, their existing design presents compatibility issues during integration with micro-electronic systems. The recent development in the new micro-scale device pattern referred to as micro-supercapacitors (MSCs) holds great potential to address those issues. MSCs rated as a promising type of micro-scale energy storage devices benefit from their intense power density, high-speed charge–discharge rate, exceptional cycling stability, and impressive safety features. Herein, we have described the recent progress in MSCs considering their physical dimensions, encompassing electrode width (w), electrode separation (d), and electrode thickness (z), all typically within the micro-scale range. This also includes various components of the MSCs such as electrode materials, electrolytes, fabrication techniques, and their integration. Furthermore, the strengths, weaknesses, opportunities, and threats of MSCs are extensively presented. In addition, a detailed discussion is presented on the utilization of self-powered MSCs in microelectronic devices. To summarize, this review has detailed the prospects and upcoming developments in self-powered MSCs.</p