Bo Jie

Hefei Science Museum Innovation Exhibits Deepening Design and Production Service Project Exhibition 6- Bo Jie

Exhibition dimensions: approximately 2.15 x 1.5 x 2.0 meters (width x depth x height)

Knowledge points:

Standing waves are two kinds of waves with the same frequency and opposite transmission direction, which are distributed along the transmission line. One of the waves is usually a reflection of the other wave. On the waveform, the positions of nodes and antinodes remain constant, giving the impression of being "stationary". Standing waves are a common physical phenomenon. The sound production principle of various instruments is related to standing waves. For example, common string instruments and wind instruments respectively use standing waves on the strings and standing waves in the orchestra to produce sound.

Participation method:

Mechatronics interaction.

The main interactive device consists of several metal rods of varying lengths and thicknesses suspended under the arch, as well as a striking hammer. The metal rod is printed with red and white stripes, which are interactive areas drawn based on the inherent waveform of the metal. When the audience holds the red stripes with their hands and strikes the metal rod with a hammer, the sound is clear and pleasant, with lingering echoes; But when the audience holds the white area with their hands and then strikes the metal rod with a hammer, the sound is dull and short.

There is a vibration mechanism on the other side of the exhibition items, with one end of the rope fixed to the oscillator and the other end fixed to the table or pulled by the audience. The audience presses the button to activate the vibration mechanism, and the oscillator drives one end of the rope to vibrate up and down. At this time, if the rope is in a tensioned state, the incident wave emitted from the vibrating end will form a standing wave with the reflected wave from the fixed end, and the audience can observe the antinodes and nodes formed on the rope. It can be clearly seen that the nodes are basically stationary, while the antinodes vibrate significantly up and down.

Design and process requirements:

Interactive Installation 1: Vertical design, arch shaped exhibition stand, with several metal rods of varying lengths and a striking hammer suspended under the arch. The surface of the metal rods is marked with stripes of different colors to indicate the positions of the antinodes and nodes. The surface of the metal rod is smooth, will not rust or discolor, and will not deform or dent due to impact. The tapping sound is crisp and pleasant, with obvious residual effects.

Interactive Device 2: Install a vibration mechanism (optional dot timer) on the booth, with one end of the rope fixed to the oscillator. There is a transparent protective device outside the vibration mechanism, and a U-shaped hole reserved at the lower end for rope vibration. The other end of the rope can be fixed on one side of the platform, or the audience can directly tighten it by hand. The demonstration effect is obvious. The vibration mechanism is stable and durable, and the rope will not be thrown to the audience during vibration.