Sensors are one of the key building blocks of the Internet of Things. As ubiquitous systems, they can be deployed everywhere. They can also be implanted under human skin, in a purse or on a T-shirt. Some can be as small as four millimetres in size, but the data they collect can be received hundreds of miles away. They complement human senses and have become indispensable in a large number of industries, from health care to construction. Sensors have the key advantage that they can anticipate human needs based on information collected about their context. Their intelligence multiplied by numerous networks allows them not only to report about external environment, but also to take action without human intervention.
Miniaturized silicon chips are designed with new capabilities in smaller form factors and better processing performance and efficiency. Costs are falling, following the Moore’s Law. The cost of bandwidth has also declined and similarly the processing costs, enabling more devices to be not just connected, but smart enough to know what to do with all the new data they are generating or receiving.
Capabilities such as context awareness and inter-machine communication are considered a high priority for the IoT. Additional priorities are the integration of memory and processing power, the capacity of resisting harsh environments, and an affordable security. Furthermore, the development of ultra low power processors/microcontrollers cores designed specifically for mobile IoT devices and a new class of simple and affordable IoT-centric smart systems will be an enabling factor. The solutions in this respect will range from micro programmed finite state machines to the use of microcontrollers. The choice is a trade-off between flexibility, programmability, silicon area, and power consumption. The devices require some form of non-volatile storage (EEPROM/FRAM/Polymer), independent of whether this will be laser trimmed at the time of manufacture, one time programmable, or electrically rewritable. Rewritable non-volatile memory is clearly preferred for achieving high throughput during production test, and allows concurrently the benefit of user memory, programmability and storage of sensor data.