What actually is nano electronics? The semiconductor people have been working with features that are 100 nm or smaller for close to 20 years. The current generation of semiconductors are classified as being 32 nm or smaller.
So we have transistor and other components that are sub-100 nm. Does that classify as nano-electronics? Or are they nano-electronic components? What classifies something as electronics? Is it the function as a system or only constituent parts? If the term refers to the system, the development of nanoscale electronics is significantly more challenging.
Consider the elements of a system. The system must do something, whether it is measure a variable, record some data, provide an output, and survive in its environment. Consider an electronic-based thermometer. The device must measure temperature, which can be accomplished by a variety of means, current flow in thermally sensitive resistor, deflection of a gauge, etc. Once the device makes this measurement, it must record the measurement or display it. Of course, these electronics must be packaged in some kind of container. Being electronics, the system requires power from somewhere. It could be from a battery inside the package. Let’s start with the existing state-of-the-art in small batteries.
Small batteries have been in the news this year. NBCNews Technology [1] has a picture of a wireless medical implant that is roughly the size of a grain of rice. The battery, which is part of the package, has a wireless connection capability for recharging it so that the device can be kept functioning. ExtremeTech [2] has an article on graphene based battery that is also roughly the size of a grain of rice. ScienceDaily [3] had an article on a battery small enough to be injected. The picture in the article shows the battery to be about the length of a grain of rice but slightly larger in diameter. From these and other releases, one can surmise that the length of a grain of rice is the smallest battery size in production today.
What are the dimensions of a grain of rice? Rice grain are a function of two characteristics. The first one is the length, which can range from under 6.2 mm for short grain to over 6.6 mm for long grain rice. The second characteristic is the ratio of the length to the diameter. This ranges from 3.1 for long grain to 1.9 for milled rice. For an approximation, one can consider the grain of rice to be 6 mm by 2mm. Consider that at the nanoscale. The dimensions are 6,000,000 nm by 2,000,000 nm! That is not small. And, that is only the battery not the rest of the electronics that needs to be included in the package. Consequently, reducing the size of the power for the electronics will be a major challenge. Other portions of the nano-electronics will be covered in future blogs. We have a long way to go to get to true nanoscale electronic systems.
References:
[1] http://www.nbcnews.com/tech/innovation/woireless-medical-implan-smaller-grain-rice-n109431
[3] http://www.sciencedaily.com/releases/2014/02/140218143330.htm
