Skin-conformable biosignal monitoring sensor by applying organic-inorganic hybrid photo transistor and manufacturing method thereof

A biosignal monitoring sensor, comprising:

• a substrate;
• a light source which is connected to the substrate;
• a first photo transistor which is connected to the substrate and has a first light absorption layer;
• and
• a second photo transistor which is connected to the substrate and has a second light absorption layer,
• wherein the first photo transistor operates in a first sensing mode and the second photo transistor operates in a second sensing mode,
• wherein the first photo transistor and the second photo transistor transmit feedback to each other to be controlled to be on/off, such that when the first photo transistor is turned on, the second photo transistor is turned off, and when the second photo transistor is turned on, the first photo transistor is turned off,
• wherein the first photo transistor outputs a constant signal level at a low heart rate, a signal level being increased at a high heart rate, such that a higher heart rate results in a greater signal level,
• wherein the first photo transistor transmits a feedback to the second photo transistor based on a magnitude of a first signal output from the first photo transistor, and the second photo transistor transmits a feedback to the first photo transistor based on a frequency of a second signal output from the second photo transistor, the first and second signals corresponding to a biosignal monitored by the biosignal monitoring sensor, and
• wherein in the first sensing mode, the first photo transistor operates as a low power sensor at the low heart rate, and in the second sensing mode, the second photo transistor operates as a high precision sensor at the high heart rate.