Pressure sensor and pressure sensing method

A pressure sensing method comprising:

• applying an alternating current (AC) signal to a gate of a sensor thin film transistor (TFT) comprising a piezoelectric gate insulating layer;
• detecting a drain current from the sensor TFT, the drain current being generated in response to the AC signal;
• obtaining a remnant polarization value based on the drain current;
• and
• sensing a pressure based on the remnant polarization value,
• wherein when an amplitude of the AC signal applied to the gate is VGamp, an amplitude of the drain current is IDamp, and an average drain current value is IDmean, the remnant polarization value is in proportion to a value of
• V
• G
• amp
• ⁢
• ⁢
• I
• D
• mean
• I
• D
• amp
• ,
• and the sensing the pressure comprises sensing the pressure by using a variation in the remnant polarization value.

A pressure sensor comprising:

• a substrate comprised of a flexible material;
• a sensor thin film transistor (TFT) disposed on the substrate and comprising a gate insulating layer, wherein the gate insulating layer comprises a combination of an organic material and an inorganic material;
• and
• a pressure sensing unit configured to obtain a remnant polarization value based on a drain current detected by the sensor TFT, and to sense pressure based on the remnant polarization value,
• wherein when an amplitude of an AC signal applied to a gate of the sensor TFT is VGamp, an amplitude of the drain current is IDamp, and an average drain current value is IDmean, the remnant polarization value is in proportion to a value of
• V
• G
• amp
• ⁢
• ⁢
• I
• D
• mean
• I
• D
• amp
• ,
• and the pressure sensing unit is configured to sense the pressure by using a variation in the remnant polarization value.