Interactive beer mat

Researchers at the University of Munich and Saarland University have developed a rather ludicrous interactive beer mat for the support of entertainment activities in pubs.

Its flat cylindrical body contains the electronics and a rectangular recess on the top side holds a conventional rectangular beer mat (to absorb liquids and provide advertising space).


Inside the beer mat, a gravity sensor senses motion and orientation in space and a pressure sensor monitors the weight resting on it.

The mat can be used as a voting device. While raising the glass is associated with a positive reaction, a negative vote can be given by raising the glass and explicitly turning the mat upside down. Both votes are detected by a drop in the weight measurement and distinguished by the direction of the gravity measurement after this drop. Mats which still contain glasses are counted as abstentions.


Voting can be used in song contests or in karaoke bars to give immediate feedback to the singer. In sports bars, the decisions of the referee on the TV screen are often cause of discussion, and the collective voting can here convey the average opinion of the local pub crowd.

A second activity, picking up the mat and flapping it with the hand, can be used to signal another order to the waiting staff. The amplitude of the acceleration sensor data can be understood as the urgency of the order and by shaking a stack of mat in one hand you can also express the number of ordered drinks.

By Andreas Butz and Michael Schmitz.
PDF of the project.