A Novel Design Portable Plugged-Type Soil Microbial Fuel Cell for Bioelectricity Generation

Soil microbial fuel cells (SMFCs) are a promising cost-effective power source for on-demand electricity generation applications. So far, reported SMFC configurations are usually bulky and hard to setup. In this study, a low-cost portable plugged-type SMFC (PSMFC) was designed and fabricated for on-demand micropower generation. The PSMFC can be activated just by plugging into natural wet soil, which is easy to access in the natural condition. The PSMFC uses carbon-based electrodes for cost-effectiveness. After setting the PSMFC into the soil to activate, it started to produce electricity after 1 h and reached the power density of 7.3 mW/m2 after 48 h. The proposed PSMFC can potentially generate electricity for remote sensors or soil sensing systems.

Virtual Laboratory to Support a Practical Learning of Micro Power Generation in Indonesian Vocational High Schools

The rapid changes in industrial revolution 4.0 demand change in education, especially at vocational education. Teachers in Vocational High School (VHS) in Indonesia are expected to bring technology-based innovations to achieve success in learning. Learning facilities are one of the factors supporting the success of learning class. Ideally, Indonesian Vocational High Schools have facilities and infrastructure following industrial. Currently, schools have difficulty providing learning support facilities and infrastructure following those in the industry. Thus, the equipment in the school laboratory is irrelevant to the existing equipment in the industry. The practicum apparatus gap between VHS and industry requires appropriate and effective solutions. The gap occurred in practical learning of micro power generation Indonesian VHS. On the other hand, virtual laboratories in the learning process can help students learn an object that cannot be presented in the classroom. By using virtual laboratories, students learn to use industry apparatus through virtual forms. This research aims to overcome the problem of practical learning in VHS, especially on practical learning of micro power generation through the virtual laboratory. This study used the 4D model approach (Define, Design, Develop, and Disseminate). The result showed that the virtual laboratory of micropower generation effectively supported learning and transfer of knowledge in practical learning, especially during the covid 19 pandemics.

A water-activated battery based on activated carbon

In this research, a novel property of activated carbon powder (AC powder) has been utilized to realize a disposable paper-based battery. AC powder was loaded on a 3D carbon paper substrate to make the anode. The cathode was integrated directly on the paper-based battery case by coating multiwalled carbon nanotube mixed with potassium ferricyanide on a side of a sheet of filter paper, the other side worked as a paper-based proton exchange membrane. This design provides a simple but practical disposable water-activated battery. The developed battery generated the maximum power density of 10.4 µW/cm2 at the AC powder concentration of 17 mg/cm2. Although, the output power of the battery is low, it is made of low-cost and abundant materials, and therefore being able to scale up. The battery is a disposable and on-demand micropower generation activated anytime, anywhere by water.

Micropower Generation Using Cross-Flow Instabilities: A Review of the Literature and Its Implications

Emergence of increasingly smaller electromechanical systems with submilli-Watt power consumption led to the development of scalable micropower generators (MPGs) that harness ambient energy to provide electrical power on a very small scale. A flow MPG is one particular type which converts the momentum of an incident flow into electrical output. Traditionally, flow energy is harnessed using rotary-type generators whose performance has been shown to drop as their size decreases. To overcome this issue, oscillating flow MPGs were proposed. Unlike rotary-type generators which rely upon a constant aerodynamic force to produce a deflection or rotation, oscillating flow MPGs take advantage of cross-flow instabilities to provide a periodic forcing which can be used to transform the momentum of the moving fluid into mechanical motion. The mechanical motion is then transformed into electricity using an electromechanical transduction element. The purpose of this review article is to summarize important research carried out during the past decade on flow micropower generation using cross-flow instabilities. The summarized research is categorized according to the different instabilities used to excite mechanical motion: galloping, flutter, vortex shedding, and wake-galloping. Under each category, the fundamental mechanism responsible for the instability is explained, and the basic mathematical equations governing the motion of the generator are presented. The main design parameters affecting the performance of the generator are identified, and the pros and cons of each method are highlighted. Possible directions of future research which could help to improve the efficacy of flow MPGs are also discussed.