"IR" is an acronym for "infrared." Infrared is a form of electromagnetic wave. In the electromagnetic spectrum, infrared waves come in just below visible light. IR remote controls use an LED source to generate an infrared carrier wave. Pressing a button on the remote modulates the infrared wave, producing a Morse-code-like signal, which the IR sensor in the receiving device detects, translates and responds accordingly to. To prevent an IR remote-controlled device from responding to the remote control's commands, you have to block the infrared signal so that the receiving device never detects it.
Block the Infrared Signal from the Receiving Device
Locate the IR sensor on the receiving device the remote is used to control. Generally the IR sensor sits behind a plastic window on the front panel of the electronic device (such as a TV, cable box, DVD player or stereo). It looks like a small lens or bulb.
Cut a piece of tape big enough to conceal the sensor. Adhere the tape to the area of the receiving device where the IR sensor is located. The tape should effectively conceal the IR sensor.
Paint the tape with a coating of nail polish. Nail polish blocks infrared light. That's why if you ever go into the hospital for a procedure that involves the use of a pulse detector (which uses infrared light to detect your heartbeat), you are instructed not to wear nail polish.
Block the Infrared Signal from the IR Remote Control
Locate the IR transmitter on the remote control. Generally the IR transmitter sits behind a plastic window on the front of the remote control. It looks like a small bulb.
Cut a piece of tape big enough to conceal the sensor. Adhere the tape to the area of the remote control where the IR transmitter is located. The tape should effectively conceal the IR transmitter.
Paint the tape with a coating of nail polish. Nail polish blocks infrared light.
Things You'll Need
Actually just about any substance, if it’s dense enough, can be used to block the infrared waves transmitted from an IR remote control. That’s why, if the IR sensor on a receiving device is obstructed by something as innocuous as a book or some other object, the remote control doesn’t work. Covering the IR sensor or transmitter with a piece of tape coated with nail polish is just a more deliberate way to block the IR remote control signals.