Apparatus and methods for sensing

A communication device comprising an apparatus, said apparatus comprising:

• a sensor arrangement comprising a plurality of sensor cells, wherein a first sensor cell of the plurality of sensor cells comprises a first single transistor and a first sensor, the first single transistor being electrically coupled to the first sensor, the first sensor comprising a first material having an impedance which changes in response to a first sensed attribute, and wherein a second sensor cell of the plurality of sensor cells comprises a second single transistor and a second sensor, the second single transistor being electrically coupled to the second sensor, the second sensor comprising a second material having an impedance which changes in response to a second sensed attribute;
• first selection circuitry configured to provide a gate input signal to a gate of the first single transistor in order to cause the first sensor to sense the first sensed attribute based upon a change in impedance or provide the gate input signal to a gate of the second single transistor in order to cause the second sensor to sense the second sensed attribute based upon a change in impedance;
• second selection circuitry comprising an analogue multiplexer configured to receive a complex output signal from one of the first sensor cell or the second sensor cell, wherein the complex output signal comprises both real and imaginary components;
• controlling circuitry configured, in response to receiving external instructions, to:
• in a first instance in which the external instructions comprise an instruction to sense for the first sensed attribute, cause the first selection circuitry to send the gate input signal to the gate of the first single transistor in order to cause the first sensor to sense the first sensed attribute, and
• in a second instance in which the external instructions comprise an instruction to sense for the second sensed attribute, cause the first selection circuitry to send the gate input signal to the gate of the second single transistor in order to cause the second sensor to sense the second sensed attribute;
• the communication device further comprising:
• sensing signal circuitry configured to provide an alternating current sensor input signal to one of the first sensor cell and the second sensor cell of the plurality of sensor cells,
• wherein the sensor arrangement is electrically coupled at a first end to the second selection circuitry and electrically coupled at a second end to the sensing signal circuitry such that providing the alternating current sensor input signal to one of the first and second sensor cells causes the complex output signal to provide an indication of the impedance of one of the first and the second sensor cells of the plurality of sensor cells, wherein the indication of the impedance provided by the complex output signal provides sensed attribute information about one of the first sensed attribute and the second sensed attribute, and wherein the one or more alternating current sensor input signals each have a frequency that is sufficiently low such that the apparatus is configured to detect the impedance of the first sensor or the second sensor in a range between 30 kΩ and 30 MΩ.

A method comprising:

• providing a sensor arrangement comprising a plurality of sensor cells, wherein each sensor cell of the plurality of sensor cells comprises a single transistor electrically coupled to a sensor, wherein a first sensor cell of the plurality of sensor cells comprises a first single transistor electrically coupled to a first sensor, the first sensor comprising a first material having an impedance which changes in response to a first sensed attribute, and wherein a second sensor cell of the plurality of sensor cells comprises a second single transistor electrically coupled to a second sensor, the second sensor comprising a second material having an impedance which changes in response to a second sensed attribute;
• providing first selection circuitry configured to provide a gate input signal to a gate of the first single transistor in order to cause the first sensor to sense the first sensed attribute based upon a change in impedance and a gate of the second single transistor in order to cause the second sensor to sense the second sensed attribute based upon a change in impedance;
• providing second selection circuitry, the second selection circuitry comprising an analogue multiplexer configured to receive a complex output signal from one of the first sensor cell or the second sensor cell, wherein the complex output signal comprises both real and imaginary components;
• and
• providing sensing signal circuitry configured to provide an alternating current sensor input signal to one of the first sensor cell or the second sensor cell,
• wherein the sensor arrangement is electrically coupled at a first end to the second selection circuitry and electrically coupled at a second end to the sensing signal circuitry such that the complex output signal provides an indication of the impedance of one of the first sensor cell or the second sensor cell, wherein the indication of the impedance provided by the complex output signal provides sensed attribute information about one of the first sensed attribute and the second sensed attribute, and wherein the alternating current sensor input signal has a frequency that is sufficiently low such that the impedance of the first sensor or the second sensor is able to be detected in a range between 30 kΩ and 30 MΩ.