A control method for acoustic radiation force of ultrahigh frequency ultrasound based on variable frequency pulse width modulation

Ultrahigh frequency ultrasound (>60 MHz) has emerged as a crucial actuating mechanism for non-contact manipulation, owing to its unique acoustic field properties. The traps microparticles mainly via the gradient force of radiation (ARF) on transverse plane, which is up hundreds nanonewtons. In theory, directly using ARF can strengthen manipulation force. Currently, direct implementation restricted specific and magnitude range, lacks comprehensive versatile control method. Additionally, it an calibration method that accommodates wide range. We propose variable pulse width modulation-based ARF, uses atomic microscope microcantilever mechanical sensor calibrate frequency. precise emitted by 85 MHz transducer was achieved with resolution piconewtons, range spanning from nanonewtons micronewtons, 1 kHz kilohertz. This breakthrough holds great promise expanding application ultrahigh in noncontact manipulation.