Microelectronics mounted on a piezoelectric transducer: method, simulations, and measurements

Area of Science:

• * Electrical Engineering
• * Materials Science
• * Sensor Technology

Background:

• * Development of portable, battery-operated ultrasound systems requires miniaturized components.
• * Traditional ultrasound sensors often necessitate bulky matching networks and complex wiring.
• * Reducing power consumption is critical for extending battery life in mobile sensing applications.

Purpose of the Study:

• * To design a highly integrated ultrasound sensor with driver electronics directly on the transducer.
• * To achieve small size and low power consumption for portable ultrasound systems.
• * To investigate the impact of design choices on power consumption and echo energy.

Main Methods:

• * Integration of an optimized Application-Specific Integrated Circuit (ASIC) driver stage onto a piezoelectric transducer using wire bonding.
• * Utilizing SPICE models for transducer simulation and transistor-level modeling for the driver stage.
• * Experimental measurements of system power consumption and echo energy in a pulse-echo setup.

Main Results:

• * Measured power consumption for a 16 mm diameter, 4.4 MHz transducer ranged from 95 to 130 microwatts at 1 kHz repetition frequency.
• * Power consumption directly correlates with excitation pulse width and repetition frequency.
• * Simulations closely matched experimental results and estimated ideal minimum power consumption.

Conclusions:

• * Direct integration of driver electronics onto piezoelectric transducers enables highly compact and power-efficient ultrasound sensors.
• * Eliminating interconnections between driver and transducer simplifies design and improves pulse control.
• * The designed sensor architecture is suitable for achieving very long battery operating times in portable applications.