Meet the new power of the future, nanoelectricity is on the way

Our living environment is full of various energies, such as vibrational, chemical, biological, solar and thermal energies, but most of these energies are unutilized or underutilized. Nanogenerators are based on regular zinc oxide nanowires that convert mechanical energy into electrical energy in the nanometer range, and are claimed to be the world's smallest generators.

The ubiquitous nanogenerator

The introduction of nanogenerators has pushed the limits of what is known about the size of a "generator". Nanogenerators are capable of collecting and utilizing particularly small amounts of mechanical energy in the environment. For example, the flow of air or water, the noise of various frequencies caused by the rotation of the engine and the operation of the machine, the stretching of the muscles or the stamping of the feet on the ground when a person walks, or even the slight change of the pressure in a certain place of the body brought about by respiration, heartbeat, or the flow of the blood in the human body can drive the nanogenerator to produce electric energy. Therefore, the theory of nanogenerators provides an ideal power solution for the current realization of the Internet of Things and sensor networks as well as big data.

Currently nanogenerators can be categorized into three types: the former type is piezoelectric nanogenerators; the second type is friction nanogenerators; and the third type is pyroelectric nanogenerators. They are generally used in biomedical, military, wireless communication, wireless sensing and other fields.

In today's era of rapid development of stretchable and wearable electronics, it is of great value and significance to study flexible mechanical energy harvesting devices. In recent years, the research on assembling flexible friction nanogenerators with flexible materials instead of polymer commercial films and metal sheets has become a highlight. Recently there are many research results on flexible friction nanogenerators.

Accurate testing of tiny signals is challenging

Due to the technical characteristics of nanoelectricity generation, it is necessary to test the electrical energy generated per unit area of mechanical energy, test the generated voltage, tiny current and power signals, the voltage is basically in a few volts or even a few tens of volts, while the current is generally uA or even nA level, and the power is in the mW or even uW level. How to accurately test the tiny current and power signals is more difficult, the test instrument precision and stability requirements are very high. Tektronix Keithley specializes in the testing of small electrical signals, and many Nobel Prize winners in physics have used and relied on Keithley's testing instruments. Keithley products continue to be the industry's preferred choice for nanopower generation research, and can be relied upon especially for small signal testing.

The theoretical limit of measurement sensitivity depends on the noise generated by the resistance in the circuit. Voltage noise is proportional to the square root of the product of resistance, bandwidth, and temperature. As can be seen in the figure, the source resistance limits the theoretical sensitivity of voltage measurements, meaning that being able to accurately measure a 1uV signal with a 1Ω source resistance becomes impossible if the source resistance of that signal becomes 1TΩ. Because in the source resistance of 1MΩ when the measurement of 1uV is close to the theoretical limit. At this time, the use of the usual digital multimeter is unable to complete this type of measurement, the choice of the appropriate instrument is to ensure the accurate testing of small signals prerequisite.

Nano Power Generation Test Solution

Tiny Current Signal Testing

Methods: The insulating material nano-generation technology, the general source of internal resistance in the GΩ level, the test current in the pA level, so the industry is used in the electrostatic meter 6514 + Stanford SR570 (low-noise current preamplifier) + special acquisition software for power generation current data acquisition.

Voltage test program

Methods: For voltage signal testing, it is recommended to use the new 4-series oscilloscope + voltage probe to test the V&T waveform data.