Discover the New Energy of the Future: Nanogenerators Are on the Horizon

Our living environment is filled with various forms of energy, such as vibrational energy, chemical energy, biological energy, solar energy, and thermal energy; however, most of this energy remains untapped or is utilized at an extremely low rate. Nanogenerators are based on ordered zinc oxide nanowires that convert mechanical energy into electrical energy at the nanoscale and are touted as the world’s smallest generators.

Ubiquitous Nanogenerators

Their emergence has shattered people’s preconceived notions about the size limits of “generators.” Nanogenerators can harvest and utilize even the tiniest amounts of mechanical energy from the environment. For example, the flow of air or water, the rotation of an engine, the operation of machinery, and the resulting noise of various frequencies; the contraction and expansion of muscles or the impact of feet on the ground as a person walks; and even the subtle changes in pressure within the human body caused by breathing, heartbeats, or blood flow—all of these can drive nanogenerators to produce electrical energy. Therefore, nanogenerator technology provides an ideal power solution for the current development of the Internet of Things (IoT), 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 generally applied in fields such as biomedicine, military applications, wireless communications, and wireless sensing.

In today’s era of rapid development in stretchable and wearable electronics, research into flexible mechanical energy harvesting devices holds significant value and importance. In recent years, research focusing on assembling flexible triboelectric nanogenerators using flexible materials to replace commercial polymer films and metal foils has emerged as a highlight. There have been numerous research achievements in the field of flexible triboelectric nanogenerators recently.

Precise Measurement of Microscopic Signals Presents Significant Challenges

Due to the technical characteristics of nanogenerators, research requires measuring the electrical energy generated per unit area of mechanical energy, as well as the resulting voltage, minute currents, and power signals. Voltage typically ranges from a few volts to tens of volts, while currents are generally in the microampere (μA) or nanoampere (nA) range, and power is in the milliwatt (mW) or microwatt (μW) range. Accurately measuring such minute currents and power signals is challenging and places extremely high demands on the precision and stability of test instruments. Tektronix Keithley specializes in the measurement of minute electrical signals; numerous Nobel Prize laureates in Physics throughout history have used and trusted Keithley test instruments. In nanogenerator research, Keithley products remain the industry’s top choice, particularly for the reliable measurement of minute 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, the source resistance limits the theoretical sensitivity of voltage measurements. In other words, while it is possible to accurately measure a 1 μV signal from a 1 Ω source resistance, such a measurement becomes impossible if the source resistance increases to 1 TΩ. This is because measuring 1 μV with a source resistance of 1 MΩ is already close to the theoretical limit. Under these conditions, a standard digital multimeter cannot perform such measurements; selecting the appropriate instrument is essential for ensuring accurate testing of minute signals.

Nanogenerator Testing Solutions

Testing of Microscopic Current Signals

Method: Nanogenerator technology using insulating materials typically has a source resistance in the GΩ range, with test currents at the pA level. Therefore, the industry generally employs a 6514 electrometer + Stanford SR570 (low-noise current preamplifier) + dedicated data acquisition software to collect current data from the nanogenerator.

Voltage Testing Solution

Method: For voltage signal testing, we recommend using a new Series 4 oscilloscope with a voltage probe to capture V&T waveform data.