Synthesis and fabrication of self-sustainable triboelectric energy case for powering smart electronic devices

In recent times, Triboelectric Nanogenerators (TENG) have attained the focus of the scientific community due to its potential as a medium to harvest mechanical energy from the ambient environment. Human motion has been attributed as a source of mechanical energy to drive electronic devices and sensors through TENG. Based on the principles of single electrode TENG, we have developed a Triboelectricity based Stepping and Tapping Energy Case (TESTEC) which magnifies the prospect to power touch electronic devices by utilizing finger tapping and stepping motion. This novel case was constructed with two single electrode TENG operating through the triboelectric mechanism between human skin and Polyethylene terephthalate (PET) film on the front part and Nitrile Butadiene Rubber (NBR) and PET film on the back part. This cost effective device was further tested by attaching with a cell phone at variable load frequency, airgap and finger combinations where the output response increased with the increased frequencies (60–240 BPM) and air gap (1 cm–5 cm). Maximum output voltages of 14.8 V and 50.8 V were obtained for the front and back parts, respectively. Besides, maximum output powers were observed to be 3.78 W/m2 at 0.46 MΩ and 6.21 W/m2 at 1.02 MΩ, respectively. Also, the device was tested by integrating with conventional electronic components including capacitors, bridge rectifiers and 15 LEDs. Based on the results, a electrical circuit has been proposed to power touch cell phones. The device was further modified using Silver (Ag) nanoparticles in the front part. The modified TESTEC provided higher output response compared to the primary TESTEC. The TESTEC can be a self sustainable way to power touch electronic devices which can reudce the necessity to charge electronics devices in the conventional way

KNN based piezo-triboelectric lead-free hybrid energy films

In recent times, the triboelectric and piezoelectric effects have garnered significant attention towards developing advanced material composites for energy harvesting and sensory applications. In this work, potassium sodium niobate (KNN) based energy films (EF) have been developed to utilize mechanical energy while simultaneously taking advantage of triboelectric and piezoelectric mechanisms. The KNN particles were synthesized using a wet ball milling technique and then incorporated into a polyvinylidene difluoride (PVDF) matrix together with addition of multi wall carbon nanotubes (MWCNT). The film was used to develop a piezoelectric nanogenerator (PENG) fitted with copper electrodes. The piezoelectric output of the film was further tested utilizing copper electrodes, at variable tapping frequency (60 BPM to 240 BPM) and pressure (10–40 psig) were used when activating the pneumatic piston. The open circuit voltage increased with the increase of both tapping frequency and pressure. The maximum piezoelectric output voltage was observed to be 35.3 V while the maximum current was noted as 15.8 µA. The films also showed unique output signals for different types of deformations performed under hand pressure. The film was further utilized to build a piezo-triboelectric hybrid nanogenerator to check its hybrid performance. The maximum output was observed to be 54.1 V and 29.4 µA. This film was integrated with conventional electronic components (bridge rectifiers, resistors, and capacitors) and tested for its ability to harvest energy. The hybrid nanogenerator can charge a 0.1 µF capacitor to 9.4 V in 60 s. The optimum output power for the device was measured to be 0.164 W. The film was further attached with a Kapton film and showed a hybrid output of 113.2 V. This experiment endorsed the potential of the KNN based energy films for multifunctional applications like force, pressure, and motion sensing as well as lead free energy harvesting

Polymer Based Triboelectric Nanogenerator for Cost‐Effective Green Energy Generation and Implementation of Surface‐Charge Engineering

Performance of triboelectric nanogenerators for harvesting mechanical energy from the ambient environment has been limited by structural complexity, cost-effectiveness, and mechanical weakness of materials. Herein, a cost-effective vertical contact separation mode triboelectric nanogenerator using polyethylene (PE) and polycarbonate (PC) in a regular digital versatile disc is reported. This cost-effective nanogenerator with simplified structures is able to generate an open-circuit voltage of 215.3 V and short-circuit current of 80 μA. The effects of the distance of impact and the air gap between the triboelectric layers have also been tested from 3 to 9 cm, and 0.25 to 1 cm, respectively. It is determined that 0.5 cm is the optimal air gap. The nanogenerator is also tested in different real-life scenarios including stresses produced by a moving car, walking, and a rolling skateboard over the nanogenerator. The surfaces of the triboelectric layers are further modified by surface-charge engineering which induced a 460% increase in the output power. These tests reveal a significant electrical response and mechanical stability under stress. In summary, this study demonstrates that the relatively inexpensive PE and PC triboelectric pair has the potential to be used for highly efficient, mechanically robust triboelectric nanogenerators

Flexible Bielectrode-Based Highly Sensitive Triboelectric Motion Sensor: A Sustainable and Smart Electronic Material

The self-powered and autonomous sensors are incredibly important in advanced engineering, especially defence science. The increasing necessity of simple and smart electronics requires to be sustainably flexible, wearable, and waterproof. Triboelectricity has been a widely used mechanism for motion sensing nowadays. Almost all devices based on triboelectricity require contact between two surfaces. Herein, a touchless triboelectric motion sensor for human motion sensing and movement monitoring is developed. The device was primarily fabricated using simple latex (cis-1,4-polyisoprene) structures and copper (electrode materials), which make it a very cost-effective device for sensory applications. The device is tested with specimens of different areas and heights in motion. The maximum output of the device is noted as 12 V at a specimen height of 5 cm. Further different types of human motions are applied in front of the device to ensure low energy sensitivity using triboelectric phenomena. The lightweight smart device precisely provides significant output signals for each movement of the human body which makes the device a prospective medium for motion sensing and movement monitoring which can be applied in the fields of security, energy, and medicine

Decentralized triboelectric electronic health monitoring flexible microdevice

Versatile applications of triboelectric nanogenerator as a microsystem component have widened the access to advanced healthcare monitoring and green energy systems. Recent research on wearable electronic technologies has been focusing on more complex architecture and costly materials for sensory applications resulting in less commercial feasibility. Here, we report a biocompatible, cost-effective, highly sensible, structurally simple, multifunctional and wearable triboelectric nanogenerator (TENG) as a universal health monitoring device. This triboelectric universal health monitoring device (TUHMD) was fabricated with cellulose paper and polydimethylsiloxane (PDMS)/polytetrafluoroethylene (PTFE) copolymer electrodes. This device demonstrated high sensitivity and notable identical signals on diverse body motions related to body muscles and respiratory system by mechanical triggering. The device was also observed to be sensitive to vocal cord vibration. Integration of this device with computer-aided system offers real-time data of physiological movement, potentially useful for personalized medicine, rehabilitation and remote monitoring of patients. The device was also tested from 30 to 90 beat per minute (BPM) load frequencies to observe the triboelectric performance of the device. TUHMD showed response as a triboelectric nanogenerator with a range of 12 V with negligible charge accumulation, along with a maximum capacitive performance of 11 F. This smart device showed a potential to be an advanced biomedical sensor for maintaining full health care or monitoring applications

Polymer Based Triboelectric Nanogenerator for Cost‐Effective Green Energy Generation and Implementation of Surface‐Charge Engineering

Performance of triboelectric nanogenerators for harvesting mechanical energy from the ambient environment has been limited by structural complexity, cost-effectiveness, and mechanical weakness of materials. Herein, a cost-effective vertical contact separation mode triboelectric nanogenerator using polyethylene (PE) and polycarbonate (PC) in a regular digital versatile disc is reported. This cost-effective nanogenerator with simplified structures is able to generate an open-circuit voltage of 215.3 V and short-circuit current of 80 μA. The effects of the distance of impact and the air gap between the triboelectric layers have also been tested from 3 to 9 cm, and 0.25 to 1 cm, respectively. It is determined that 0.5 cm is the optimal air gap. The nanogenerator is also tested in different real-life scenarios including stresses produced by a moving car, walking, and a rolling skateboard over the nanogenerator. The surfaces of the triboelectric layers are further modified by surface-charge engineering which induced a 460% increase in the output power. These tests reveal a significant electrical response and mechanical stability under stress. In summary, this study demonstrates that the relatively inexpensive PE and PC triboelectric pair has the potential to be used for highly efficient, mechanically robust triboelectric nanogenerators