What Materials Can Block a Wi-Fi Signal?

Odds are that you have probably accessed the Internet with a wireless device like a smartphone, tablet, or laptop. Have you ever been frustrated by a poor-quality or slow connection? In this science project, you will learn about one aspect of getting good reception: materials that can physically block Wi-Fi signals. Before you start, you will need to learn a little more background information about Wi-Fi.

Wi-Fi is the common name for a type of communication that allows electronic devices to exchange data or connect to the Internet wirelessly, meaning they do not need to connect to each other with cables. Wi-Fi devices do this using radio waves, which are a type of electromagnetic radiation. You are already very familiar with one type of electromagnetic radiation: visible light! Visible light and radio waves are just different parts of the electromagnetic spectrum (see Figure 1). Each part of the electromagnetic spectrum has a different frequency, or number of waves per second. Frequency is measured in hertz (Hz), so one hertz (1 Hz) is one cycle per second. Wi-Fi devices operate at either 2.4 or 5 gigahertz (GHz). Giga is the metric prefix for one billion (1,000,000,000, or 10⁹).