Researchers at the Universitat Autònoma de Barcelona and the Institute of Microelectronics of Barcelona have created wireless piezoelectric microdevices that stimulate individual living cells using ultrasound. The work appears in Small journal and was featured on the cover.
The devices convert mechanical energy, generated either by the cells themselves or delivered externally through ultrasound waves, into electrical signals. This conversion allows scientists to activate specific cellular processes without invasive procedures. The technology operates at the single-cell level, offering unprecedented precision in cell manipulation.
Piezoelectric materials generate electrical charge when mechanically stressed. By engineering these materials into microscale devices, the team created a system where ultrasound waves trigger electrical stimulation remotely. The cells need not be connected to external power sources or electrodes, eliminating conventional constraints of wired bioelectronics.
The dual capability stands out. The microdevices respond to forces generated by living cells themselves, enabling a form of cellular sensing. Simultaneously, external ultrasound application provides researchers with direct control over stimulation timing and intensity. This combination creates both passive monitoring and active intervention possibilities.
Applications span neuroscience, cardiac research, and developmental biology. Researchers could stimulate neural tissue to map brain circuits, trigger muscle contractions to study cardiac function, or activate specific cells during developmental processes. The noninvasive nature reduces tissue damage compared to electrode-based approaches.
The work addresses a longstanding challenge in bioelectronics. Previous wireless stimulation methods relied on magnetic fields or light, each with penetration depth limitations. Ultrasound penetrates deeper into tissue while remaining safe for biological systems, making it superior for reaching cells in dense tissues.
Limitations include device fabrication complexity and the need for precise ultrasound calibration to avoid off-target effects. Translation to human applications requires extensive safety testing and validation of specificity.
The research demonstrates