Lateral Field Excited Bulk Acoustic Wave Sensors (2010 – Present) The Lateral Field Excited (LFE) Bulk Acoustic Wave (BAW) sensor is a type of Quartz Crystal Microbalance (QCM). Unlike the commonly used Thickness Field Excited (TFE) QCM, the LFE sensor has both electrodes on one side, leaving the sensing surface bare. This allows the LFE