Professor Luo Jikui and Associate Professor Jin Hao‘s group, together with Professor Xuan Weipeng from Hangzhou Dianzi University, recently published a paper in Nature Communications titled “Multi-mode piezoelectric radiation-based microantennas and miniaturized wireless sensing unit driven by bulk acoustic waves.”
With the rapid development of the Internet of Things, wearable electronics, and implantable medical devices, building ultra-compact, low-power, wirelessly communicable systems has become a major direction in micro-nano electronics. Traditional antenna dimensions, typically constrained by electromagnetic wavelengths, face bottlenecks in micron-scale systems including low radiation efficiency and integration difficulties.
This research proposes a piezoelectric microantenna (PE μ-antenna) based on acoustic resonance driving and constructs a miniaturized wireless sensing unit. The microantenna achieves stable radiation at 1.85 GHz and 3.91 GHz with gains of –32.96 dBi and –20.5 dBi, respectively. Compared to existing piezoelectric transmitters, the device achieves an improvement of over four orders of magnitude in both radiation efficiency and size miniaturization. The study further introduces high-overtone bulk acoustic resonators (HBARs), leveraging their high quality factors to achieve multi-frequency efficient radiation and enhanced wireless transmission capabilities. The device is constructed as one of the smallest wireless sensing units to date, enabling stable detection of temperature and strain within a range of approximately 1 meter.
On the theoretical side, the study first established a radiation theory model for piezoelectric microantennas, demonstrating that under bulk acoustic wave excitation, oscillating dipoles generated within the piezoelectric film can effectively radiate electromagnetic waves, achieving energy conversion from acoustic vibration to electromagnetic radiation—a mechanism distinct from the current radiation mode of conventional conductor antennas. In terms of device implementation, the PE μ-antenna built on a thin-film bulk acoustic resonator achieves an effective operating area of just 0.0196 mm². The HBAR-based microantenna structure, benefiting from coupled resonant effects between high-order modes and fundamental modes and high quality factors (Q > 1000), achieves efficient radiation at multiple discrete frequency points. The wireless sensing unit, with the same effective area of 0.0196 mm², achieves a wireless transmission distance of up to 1 m, with a temperature sensitivity of –27.8 ppm/°C over the range of 30–200 °C and a temperature measurement error within ±2 °C. The strain sensitivity is –0.13 ppm/με over the range of 0–1000 με with a strain measurement error within ±65 με.
This study proposes and validates a new paradigm for miniature antennas based on piezoelectric radiation mechanisms, achieving a complete breakthrough from fundamental mechanisms and device design to system integration.
Link: https://doi.org/10.1038/s41467-026-70058-2
