Array of time reversal transceivers: An application to acoustic focusing

Time reversal is an efficient method to focus a wave whatever the complexity of the propagation medium. Twenty years ago, it has been applied to focus acoustically a wave in a room. Here, in a first part, we present a new prototype of time reversal mirror made of up to 32 time-reversal transceivers. This new architecture with direct memory writing/reading allows to perform time reversal even with a low power computer unit. Realtime time-reversal algorithms to pre-process an acoustic audio stream is described. In the second part, we show that this device is able to remotely focus an elastic wave on a plate. The focusing is analyzed using the DORT method.