Tree-mounted machines connect to web app to let users knock on wood remotely

Knock On Wood is an internet-connected machine that lets people perform the superstition of knocking on wood even when they have no wood nearby. Designed by Shashwath Santosh and Nithin Eluvathingal, each device is mounted against a tree and uses a physical mechanism to make a knock when someone presses a button in a web app. The project turns a familiar ritual into a remote, tangible interaction: a digital command produces a real sound and movement elsewhere.

The knockers connect over Wi-Fi to a central server, so users can activate devices from different locations around the world. For example, someone browsing on a phone or computer in a Tokyo café could trigger a machine in New York’s Central Park. The woodland prototypes use a portable Wi-Fi hotspot where standard internet access is unavailable. The design belongs to the ongoing series Machines Responding to Superstitions, which uses engineering and industrial design to explore everyday beliefs and rituals. Rather than treating the superstition as merely symbolic, the project builds a network that lets people enact it through technology, raising questions about how machines can preserve, reinterpret, or make distant cultural practices accessible.