Flexible Electronics for Wireless Communication: A Technology and Circuit Design Review With an Application Example

There is a practical gap between conventional rigid electronics and bendable items from daily life, such as paper, tape, textiles, and the human body. This space can be bridged by flexible transistor technologies, which typically offer bendability, a light weight, ultrathin dimensions, transparency, some stretchability, suitability for large areas, and a low cost. Thanks to the continuous increase of the maximal operation frequency of flexible electronics, wireless communication is becoming one of the promising enablers for many new applications and is widely studied. For a long time, electronics have advanced in terms of speed, power consumption, integration density, and cost. In particular, reductions in feature sizes, which lead to improvements in integration density, are expected to keep slowing down, e.g. due to thermal noise constraints. This trend has long been predicted, and it has motivated the investigation of multiple alternative electronic technologies, including mechanically flexible ones.