The portable design of small DC fans is characterised by three main aspects: compactness, light weight and portability. Firstly, their size is generally smaller than that of conventional fans, while the body casing is usually made of lightweight materials such as plastic and aluminium alloy, making the fan light enough to fit in a pocket or carry bag. Secondly, the fans are usually equipped with a charger that can be connected to devices such as computers and mobile power sources via a USB port, making them easy to carry around. Finally, small DC fans are designed with the user experience in mind. For example, their blades and protective covers are usually smaller than those of conventional fans, which reduces air resistance and increases air speed, while also reducing power consumption.

Small DC fans have a wide range of potential applications, mainly in the following areas:

1. Outdoor activities: In outdoor activities, small DC fans can provide cool air to help people stay comfortable in hot weather. For example, when camping, hiking or playing outdoor sports, small DC fans can help people stay cool and improve the quality and efficiency of their activities.

2. Travelling: Small DC fans are one of the essential items for travelling. They can help people stay cool while travelling and can also be used as a portable air purifier to help people stay healthy in environments with poor air quality.

3. Office: Small DC fans can help people stay comfortable in the office. They can be placed on desks or bookshelves to provide cool air, and can also be used as a small air purifier to help people stay healthy in environments with poor air quality.

4. Medical equipment: Small DC fans can also be used in medical equipment, such as operating theatres and intensive care units, to provide cool air and help patients stay comfortable.

In short, the portable design and wide application potential of small DC fans make them one of the essential items in people's daily life and work.