Uses of Radiation

The above list is based on the following chart of predominate radionucluides present in uranium decay.

The idea of atomic batteries has been around for over 100 years. They seek to use charged particles released from radioactive materials to generate a current. In the past these batteries have been used in space missions as well as military applications. New developments that hope to decrease their size will allow them to be used in implanted medical devices and low voltage electrical devices.

Atomic batteries offer a lifespan relative to the half-life of the radioactive material being used, meaning that they can provide power for decades before they need to be replaced. The most common type of atomic battery uses betavoltaics. This means that a semiconductor material is used to absorb beta decay and generate a current.

Semiconductor materials are unfortunately decayed by beta particles. As a result the batteries don’t last as long as they could. A team at the University of Missouri have designed an atomic battery that uses a liquid semiconductor, which allows it to degrade slower. Another design to solve this problem mixed the radioactive material with a phosphor (light-giving substance) and surround it with a transparent material. The semiconductor is replaced by a photoelectric surface of silicon. The radiation never passes beyond the transparent material and the light is collected and converted into electricity.

Cornell University has developed an atomic battery that uses a piezoelectric cantilever to produce electricity. Beta decay charges the cantilever which is then attracted to a positively charged thin film. When they touch, the two cantilevers receive equal charges and repel each other. The movement repeats and creates an electric charge.

The following background information on semiconductors has been included because of their direct use in atomic/nuclear batteries. Semiconductors are a ubiquitous part of modern society. They are the heart that keeps the pulse of technology pumping as they are found in microprocessor chips and transistors. Anything that is computerized or uses radio waves depends on the utilization of semiconductors. Semiconductors are mostly composed of silicon or some sort of crystalline inorganic solid (Group 4A has 4 valence electrons which offers an ease of uniformity when crystallizing). This causes them to partially be considered resistors as they modify the permeability of electricity between objects. To determine the magnitude of conductibility, materials with different periodic properties are used. One particular property that is of importance when considering material usage is the variance in electron mobility. Because of material consistency in a semiconductor, the range of electricity that is allowed to pass through is made controllable. This control allows for the alteration of operations’ speed, temperature, and power of electronic devices. In reference to atomic batteries, two main types of semiconductors are deliberated upon: silicon and germanium, silicon being the more common of the two. Silicon is easier to obtain and more popularly shipped and manufactured around the world. Silicon in solar panels last, on average, up 20 years. If this is an accurate analogous for the durability of silicon as semiconductors this would prove that it lasts longer and is the most widely accepted choice. Silicon is also easier to process and experiences less leakage than most materials commonly used in semiconductors. In terms of price, Silicon comes in as the cheapest material across all grades. Regular grade silicon costs $0.50 per gram. Germanium is an avid competitor in the conductive world. It is similar to silicon in that they are periodic group neighbors. However, its availability is not as highly ranked as that of silicon seeing as germanium is the fiftieth most commonly found element and silicon is the second most abundant element in the Earth’s crust.