Scientists have developed a “dancing” film that can convert tiny amounts of energy into usable energy!

Energy shortage has always been a topic of great concern to all countries. The level of a country’s economic development is always closely related to its energy situation. There are two ways to solve the energy shortage, one is to develop the application of new energy, and the other is to increase the efficiency of the developed energy. With the development of the times, the idea of developing new energy is not limited to developing visible energy in daily life, but also converting some of the tiny energy in our daily life into usable energy. For example, some wearable devices can convert the energy generated when people exercise. The vibrations are converted into electrical energy.

Recently, Professor Takuzo Aida of the RIKEN Center for Emergency Materials Science, the University of Tokyo, and Professor Daigo Miyajima of the RIKEN Center for Emergency Materials Science designed an actuator that can self-start according to changes in air humidity or light conditions. When the external humidity changes Or when the lighting conditions change, this film with a carbon-nitrogen conjugated structure will change its shape, like a dancer who loves to dance. The response speed of this film is very fast and its bending angle does not decrease after being bent 10,000 times. This design is expected to find application in a range of fields.

The material is composed of carbonitride. The synthesis process is shown in the figure below. The carbonitride is obtained by depositing on a glass substrate, and then a thin film is obtained by immersing it in hot water.

When the temperature is constant (27°C), the bending angle of the film increases as the ambient humidity decreases (Figure a below); comparing the morphological changes of the film at 20°C and 40°C, it can also be found that due to hydrogen bonding at high temperatures is damaged, the film is easily deformed (Figure b below).

When irradiated with ultraviolet light, the shape of the film changes due to the change of bonds in the photoinitiated compound film (a); and after 10,000 times of bending, the bending angle of the film has basically no attenuation (b) ; And the film morphology can be quickly restored with or without UV light (Figure c below).

The study also found that the film has a self-actuating mechanism under certain humidity conditions.

This type of carbon-nitrogen conjugated polymer structure can change rapidly under different humidity and light conditions to respond to external stimuli. The advantage of this type of material is that its actuation energy is very small. In the future, this type of self-actuator will There is an increasing trend toward low-energy startup.