BLOCKINESS AND FIDELITY IN WATERMARKING

摘要

A device to measure pressure is disclosed. In one embodiment, the device comprises at least one element comprising two layers (24, 26) separated by a space, wherein a dimension of the space changes over a variable time period in response to a voltage applied across the two layers and a measuring module configured to measure the time period, wherein the time period is indicative of the ambient pressure about the device.