This paper presents recent developments in an extremely compact, wireless impedance sensor node for combined use with both impedance method and low-frequency vibrational data acquisition. The sensor node, referred to as the WID3 (Wireless Impedance Device) integrates several components, including an impedance chip, a microcontroller for local computing, telemetry for wireless data transmission, multiplexers for managing up to seven piezoelectric transducers per node, energy storage mediums, and several triggering options into one package to truly realize a self-contained wireless active-sensor node for SHM applications. Furthermore, we recently extended the capability of this device by implementing low-frequency A/D and D/A converters so that the same device can measure low-frequency vibration data. The WID3 requires less than 60 mW of power to operate and is designed for the mobile-agent based wireless sensing network. The performance of this miniaturized device is compared to our previous results and its capabilities are demonstrated.