Meet the new power of the future: nanopower generation is coming

Our living environment is filled with a variety of energy, such as vibrational energy, chemical energy, biomass energy, solar energy, and thermal energy. However, most of this energy is either unused or extremely underutilized. Nanogenerators, based on regular zinc oxide nanowires, convert mechanical energy into electrical energy within the nanometer range and are considered the world's smallest generators.

Ubiquitous Nanogenerators

Their advent has shattered the perceived limits of generator size. Nanogenerators can harvest and utilize extremely minute amounts of mechanical energy from the environment. For example, noise of various frequencies caused by the flow of air or water, the rotation of engines and machinery, the contraction of muscles or the impact of feet on the ground when walking, and even subtle changes in pressure within the human body caused by breathing, heartbeat, or blood flow can all drive nanogenerators to generate electricity. Therefore, the nanogenerator theory provides an ideal power supply solution for the current Internet of Things, sensor networks, and big data.

Currently, nanogenerators can be divided into three categories: the first is piezoelectric nanogenerators; the second is triboelectric nanogenerators; and the third is pyroelectric nanogenerators. They are commonly used in biomedicine, military, wireless communications, wireless sensing, and other fields. In today's era of rapid development of stretchable and wearable electronics, research on flexible mechanical energy harvesting devices is of paramount importance and significance. In recent years, research on flexible triboelectric nanogenerators (TGNs) assembled from flexible materials, replacing commercial polymer films and metal sheets, has become a hot topic. Recent research on these devices has yielded numerous results.

Accurately measuring tiny signals presents significant challenges.

Due to the inherent technical characteristics of nanogenerators, research requires measuring the electrical energy generated by mechanical energy per unit area, including voltage, tiny current, and power signals. Voltages typically range from a few volts to tens of volts, while currents are typically in the microamps or nanoamps range, and power levels range from milliwatts to microwatts. Accurately measuring tiny current and power signals is challenging, placing extremely high demands on the accuracy and stability of the test instruments. Tektronix Keithley specializes in testing tiny electrical signals, and numerous Nobel Prize winners in physics have used and trusted Keithley test instruments. Keithley products remain the industry's preferred choice in nanogenerator research, especially for reliable testing of tiny signals.

The theoretical limit of measurement sensitivity depends on the noise generated by resistance in the circuit. Voltage noise is proportional to the square root of the product of resistance, bandwidth, and temperature. As shown in the figure, source resistance limits the theoretical sensitivity of voltage measurements. This means that while a 1µV signal with a 1Ω source resistance can be accurately measured, the same measurement becomes impossible if the source resistance is 1TΩ. This is because measuring 1µV with a 1MΩ source resistance is already near the theoretical limit. At this point, a conventional digital multimeter cannot perform this type of measurement. Choosing the right instrument is crucial for accurately measuring tiny signals.

Nanopower Generation Test Solution

Micro-Current Signal Testing

Method: Using insulating material nanopower generation technology, the source internal resistance is typically in the GΩ range, and the test current is in the pA range. Therefore, the industry typically uses a 6514 electrometer combined with a Stanford SR570 (low-noise current preamplifier) and dedicated acquisition software to collect power generation current data.

Voltage Test Solution

Method: For voltage signal testing, we recommend using a new 4-series oscilloscope combined with a voltage probe to measure V&T waveform data.