Sensor

In the broadest definition, a sensor is a device, module, machine, or subsystem that detects events or changes in its environment and sends the information to other electronics, frequently a computer processor.

Their applications include manufacturing and machinery, airplanes and aerospace, cars, medicine, robotics and many other aspects of our day-to-day life.

For instance, if the mercury in a thermometer moves 1  cm when the temperature changes by 1 °C, its sensitivity is 1 cm/°C (it is basically the slope dy/dx assuming a linear characteristic).

In most cases, a microsensor reaches a significantly faster measurement time and higher sensitivity compared with macroscopic approaches.

[2][3] Due to the increasing demand for rapid, affordable and reliable information in today's world, disposable sensors—low-cost and easy‐to‐use devices for short‐term monitoring or single‐shot measurements—have recently gained growing importance.

Noise is a random error that can be reduced by signal processing, such as filtering, usually at the expense of the dynamic behavior of the sensor.

[5][6] The information is provided in the form of a measurable physical signal that is correlated with the concentration of a certain chemical species (termed as analyte).

Consequently, a characteristic physical parameter varies and this variation is reported by means of an integrated transducer that generates the output signal.

However, as synthetic biomimetic materials are going to substitute to some extent recognition biomaterials, a sharp distinction between a biosensor and a standard chemical sensor is superfluous.

[7] In biomedicine and biotechnology, sensors which detect analytes thanks to a biological component, such as cells, protein, nucleic acid or biomimetic polymers, are called biosensors.

The encapsulation of the biological component in biosensors, presents a slightly different problem that ordinary sensors; this can either be done by means of a semipermeable barrier, such as a dialysis membrane or a hydrogel, or a 3D polymer matrix, which either physically constrains the sensing macromolecule or chemically constrains the macromolecule by bounding it to the scaffold.

As it was fairly straightforward to fabricate a series of MOS capacitors in a row, they connected a suitable voltage to them so that the charge could be stepped along from one to the next.

[33] The typical modern CPUs, GPUs and SoCs are usually integrated electrics sensors to detect chip temperatures, voltages and powers.

Different types of light sensors
A LIDAR sensor (bottom, center), as part of the camera system on an iPad Pro . [ 29 ]