Energy Conversion at the Cuticle of Living Plants

As people became more aware of environmental issues, several designs of triboelectric energy harvesters based on biocompatible and eco-friendly natural materials have been developed in recent years. This manuscript reports a plant-based green triboelectric nanogenerator using extracted leaf powder of the Rumex vesicarius plant and PET as triboelectric layers. When hand-tapped, the developed TENG generated an open-circuit voltage (oc) of 3.86 V, and a short-circuit current (sc) of 3.78 μA, respectively. The device has the highest power density of 0.1894 μW/cm 2 at load resistances of ∼20 MΩ and can directly power up one light-emitting diode. The TENG response has been tested over 1200 cycles, confirming its remarkable stability. The proposed TENG can be a promising sustainable tool to capture mechanical energy from nature and our everyday actions and thus convert it into electricity.

2021

The paper reveals some fundamental investigations which are related to the potential difference of the plants. The main aim of the experiment was to harvest electricity from the living plants and make it useable for practical applications. The energy from the living plants has been harvested here by embedding electrodes into the plants. Comparing to the many electrode pairs which has generated highest voltage difference were used for further investigations. Other investigations including voltage profile against electrode spacing, source resistance, tree networks, embedding electrodes to the tree at different radius etc. has been tried to co-relate. This experiment also includes the measurement of power embedding the electrodes in the trees for long time. By this way, the probability of getting stable power from the living plants has been analyzed.<br>

Journal of Energy and Power Engineering

The phenomenon of electrical potential differences along the plant apoplast has been reported for more than a century. Earlier works of harvesting energy from trees reported nW range of power with a few hundred-mV open circuit voltage and near uA range short circuit current. In this work, we show that if we cut a stem into pieces, each segment would maintain nearly the same open circuit voltage and short circuit current regardless of length. Using a pico-ampere meter, we also found that the living cells in the vascular cambial and secondary xylem and phloem tissues are the source of electricity. They provide a relatively constant voltage and current to external environment for reasons still under investigation. We demonstrate that by cascading separated stems we can accumulate up to 2 V of open circuit voltage. We also demonstrate by connecting them in parallel we can increase the short circuit current.

International Journal of Renewable Energy Research, 2018

Renewable energies (RES) has been discussed and explored by researchers in the past decades, has proved that it can decline the capital cost and cost of electricity generated. Such sources such as solar energy and wind energy continue to take advantage in development, securing long-term sustainable energy for the future. Demand for these renewable energy leads to a reduction of pollution and leaning towards green energy environment. Hence, as the live tree has been discovered to be able to generate a weak source of electricity, it cannot be overlooked as those potential can be used as a power source for lowpowered devices. Thus, this paper reviews the concept of living plant energy harvest in several ways and the real-life practice of the technique. Living plant energy overview is also done together for future challenges.

International Journal of Green Energy, 2018

In the present study, bioelectricity generation using a living plant in soil was achieved by converting solar energy into electricity on the principles of plant photosynthesis. The plants Chlorophytum comosum, Chasmanthe floribunda and Papyrus diffuses were used in microbial fuel cells (MFCs) and produced, respectively, a maximum current of 25, 31 and 19 mA/m2, without the use of any nutrient or membrane. In this study, the importance of light was demonstrated by the high current values generated during daytime, and the microorganisms at the anode-rhizosphere interface were examined.

MULTILOGIC IN SCIENCE, 2019

In a recent era of modernity, a lot of trends have been set in Science and Technology. Progress towards green and autonomous energy sources includes harnessing living system and biological tissues. Sustainable energy sources, which are pollution free and environment friendly, are one of the key challenges of world's future society. For that number of emerging trends has been established but they are specific in their nature to fix the emerging or previous issues. Electricity generates green by plants via photosynthesis associated with electrochemically active microorganisms converts' metabolic energy by CO 2 , proton and electrons. Recently discovered that the cuticle-cellular tissue bi-layer in higher plant leaves functions as integrated tribo-electric generator conductor couple capable of converting mechanical stimuli into electricity. Electricity generates by a biomimetic tree having small strips of specialized plastic inside the leaf stalks release an electrical charge when bent by moving air. Such processes are known as piezoelectric effects. Artificial plants containing piezoelectric elements may harvest wind energy sufficient to contribute to a carbon-neutral energy economy. In this way, day and night electricity can sustainably be produced from biomass without harvesting the plant. Furthermore, the systems' concept is principally clean, renewable and sustainable. These technologies might be implemented in several ways, ranging from local small scale electricity providers to large scale electricity wetlands & islands, high-tech electricity & food supplying greenhouses and novel bio-refineries.

2009

Inspired by water transport in plants, we present a synthetic, microfabricated "leaf" that can scavenge electrical power from evaporative flow. Evaporation at the surface of the device produces flows with velocities up to 1.5 cm/s within etched microchannels. Gas-liquid interfaces within the channels move across an embedded capacitor at this velocity, generating 250 ms, 10-50 pF transient changes in capacitance. If connected to a rectified charge-pump circuit, each capacitive transient can increase the voltage in a 100 F storage capacitor by ϳ2-5 V. We provide estimates of power density, energy density, and scavenging efficiency.

IOP conference series, 2019

This research focused on Electrical Energy Harvesting using taro leaves colocasia esculenta L coated electrode and water droplet passed. The advantage of this research lies in the concept of hydrophobic using natural material from taro leaves colocasia esculenta L, so it is environmentally friendly. In this study using an external circuit of capacitors and bridge rectifier that are connected with aluminum foil as electrodes. From the results, shows that optimal voltage and stable at three drops/second with a slope of 150 degrees produces 78 mV. Electrical energy can be produced because there are energy triggering electrons to jump. Energy obtained from the repulsion of the structure of the leaf surface morphology and the attraction of the element O (oxygen) in the water droplet triggers the surface to become more superhydrophobic. The superhydrophobic surface of the leaf as a membrane to deliver ion flows through the electrode as the way charge flows to the capacitor that is read as the voltage on the oscilloscope. Between the water droplet and the leaf surface, generate the contact angle, so the leaf surface to become superhydrophobic. The role of superhydrophobic properties and slope of the leaf surface is significant to produce electrical energy.

Living-plants have been proven to have a potential for renewable energy source by embedding pairs of electrodes into it to allow flow of ions and hence generate electricity. Multiple tests using different type of electrodes and plants suggested that voltages are produced to greater or lesser extents where combination of copper (Cu)-zinc (Zn) and Aloe Vera produces the highest voltage output. To optimize the power output from the plant, a comprehensive knowledge regarding the mechanisms of energy generation is necessary. Initial hypothesis inferred this from electrochemistry process. Therefore, the presence of trace metals from the electrodes using Flame Atomic Absorption Spectroscopy (FAAS) was investigated in the plant to gain insight into the origin of the energy production. To further justify the stated hypothesis, comparison of trace metals concentration in electrodes immersed Aloe Vera between opened and closed circuit is also investigated. The obtained result confirmed that the electrochemistry process is responsible for the mechanism of the energy production from living plant.

Journal of Earth Energy Engineering, 2023

Voltage generation was obtained using a water droplet characterization on a taro (Colocasia esculenta L) leaf surface. This method relies on the superhydrophobic effect from the contact angle between the water droplet and the taro leaf's surface allowing electron jumping and voltage generation. Water droplets were dropped on the top of taro leaf surface equipped with aluminum foil underneath as an electrode. The voltage was measured at various slope angles of 20°, 40° and 60° in a real-time basis. A digital camera was used to capture the droplet movement and characterization. It is found that the taro leaf has a surface morphology of nano-sized pointed pillars which created a superhydrophobic field. The energy generation was primarily obtained from the electron jump which was caused by the surface tension of the nano-stalagmite structure assisted by the minerals contained in the taro leaf surface. The results reported that the smaller the droplet radius (the smaller the droplet surface area), the greater the droplet surface tension and the greater the voltage generation. Furthermore, the highest voltage generation was obtained 321.2 mV at 20°-degree angle of slopes.