Electrochemical Tilt Sensors With Symmetric Concentric Electrode Pairs

This paper presented the principle, design, fabrication, and characterization of Molecular Electronic Transducer (MET) single-axis tilt sensors. The proposed sensor has a circular channel deposited with symmetric concentric electrode pairs and half-filled with a liquid electrolyte. Such inclination-dependent liquid level is detected by the differential current from the electrochemical reaction at the two symmetric concentric electrode pairs. In order to reduce the form factor, an organic solvent is added to the aqueous electrolyte to lower the surface tension force. Limited by the liquid motion and reaction rate, the sensors are capable to measure tilt angle under static conditions only. From the tilt angle stepping experiments, the performance of the proposed tilt sensors is characterized and compared. The sensors' response time is dominated by the electrochemical equilibrium arrival time. They can achieve a low discrimination threshold of 0.016 degrees and a short time constant of 0584s within the +/- 85 degrees measurement range with a power consumption of less than 0.1mW. Compared to previously reported MET tilt sensors with a parallel swirl electrode configuration, the signal-to-noise ratio and response time are improved significantly.

Automated summary

This paper presents a single-axis tilt sensor manufactured using MET technology, which exhibits superior performance and response speed. The sensor can measure tilt angle under static conditions by detecting liquid level changes through differential current. The addition of organic solvent can reduce the form factor of the sensor.