Mobile Phone Charging via Utilization of Triboelectric Effect in Harnessing Electrical Energy from Disposed Human Hair

摘要

Human hair is considered as waste material in most parts of the world and its accumulation in waste streams causes many environmental problems; it is a material considered useless in most societies. Recent studies proved that human hair has the ability to become charged with the static electricity. Keratin is found in hairs. Since keratin is a good insulator, it makes the charging of hair possible mainly by contact with another material: this phenomenon is said to be Triboelectric effect. Why won't we utilize human hair which almost anyone & anywhere in the world have and most of the time treated as wastes? In this study, we collected human hair wastes from different accessible barbershops and salons. We made this possible through the use of the principle of Triboelectric Effect. Hair has charge affinity of +45 and it is said to become highly positively charged material when brought in contact with other materials (which in this prototype is Vinyl tape with charge affinity of -100). Aided by the vinyl tape's chemical characteristics, the hair tends to give up electrons in the process, thus resulting to a significant output of electrical energy. The amount of transferred charge is [+45 nC/J - (-100 nC/J)] = 145 nC/J. Applying a contact force of 25grams in a 2.5cm wide or friction force of 1 millijoule (mJ) per cm~2 samples, the charge transferred per cm^2 is 145 nC/J × 0.001 J = 0.145 nC. The prototype works by using a minimal representation of friction to rotate the belt between two customized rollers around; a roller made up of disposed hair and another roller wrapped with vinyl tape. Each sides of the device have a brush of stranded wires placed near the rollers. The brushes then be connected to metal collectors that are collecting the charges and will be fed into a Bridged rectifier circuit to produce a stable output, and will then be stored in a super capacitor. Based on the preliminary experiments undertaken, the results shows that the Input-Output Ratio of hair used to Output Voltage (rms) is 100mg of hair is to 23VRMS. The 100mg of hair roller will lasts for about 4 months with a raw (un-rectified) output voltage of 21.4V accumulated per 5 minutes. There are 43,200 minutes per month, therefore: (43,200 minutes / 5 minutes) x (21.4V) = 8,640V raw output per month. About 288V per day of raw output voltage will be obtained. Since super capacitors are fast charging, approximately about 100V will be stored. Such output shall be optimized and regulated to charge a cellular phone. Imagine the huge quantity of output voltage can be accumulated from a low-cost prototype. 100 percent sure, it has a positive cost-benefit based on the analysis.