One could have never imagined that something nanosized, the transistor, would be an essential component of our everyday lives.

Already in the 1950s, vacuum tubes were unideal for the visions of mankind due to their bulkiness, large power consumption, and inadequate processing power.

One of the inventors, Shockley, proclaimed, “It seems to me that in these robot brains the transistor is the ideal nerve cell.”[1] With their use as switches and current amplifiers, they are integrated into all technology around us.

“It seems to me that in these robot brains the transistor is the ideal nerve cell.”

Lee de Forest’s invention of the triode vacuum tube (see Figure 1) consisted of an electrified mesh between two electrodes in a vacuum which implemented the thermionic emission effect (heating metal and knocking electrons loose with thermal energy) to amplify electrical current as well as act as a switch.

Transistors, on the other hand, are solid-state semiconductor devices with three terminals: the base, collector, and emitter (see Figure 2). Some of the notable problems imposed by vacuum tubes were their high operating voltages and power consumption needed to facilitate thermionic emission.

Furthermore, the most significant reason as to why vacuum tubes would not have been suitable for today’s technological world is due to their sheer size and lack of portability.

The first digital computer, which utilized vacuum tubes weighed 27 tonnes, consumed 200 kilowatts of electrical power and was enormous (30x3x1 meters cubed).

[2] Today, billions of transistors could fit in the size of a vacuum tube. Additionally, transistors use 100,000 times less power, are durable, and produce significantly less heat.

[3] Moore’s law states that the processing power of transistors will double every two years as their size halves. This phenomena and rapid miniaturization would not have been possible with vacuum tubes.

Figure 1: Labelled structure of a triode vacuum tube by Wikimedia

Figure 2: Labelled transistor with a schematic of how current flows through the terminal by Dummies A Wiley Brand

Nowadays, transistors are virtually everywhere and have led to the development of inventions such as the integrated circuit and the internet.

One of the first devices that incorporated transistors was the Texas Instruments’ pocket calculator. This invention enabled the public to make quick and highly accurate calculations and revolutionized the education system. Some other early commercial applications were hearing aids and pocket radios.

The technological revolution that followed was led by transistor-reliant portable phones and laptops which in turn allowed for the rapid increase in information exchange and intelligence.

Today’s most common applications of transistors are computer chips and microprocessors that allow us to store gigabytes and even terabytes of our memories, such as photos for easy accessibility.

[5] A noteworthy example is the most recent Apple processor, A13, for the iPhone 11 which has 8.5 billion transistors.

[6] Transistors enabled us to land on the moon and send off satellites deep into our solar system with their lightweight and compact design used in onboard computers and communication devices.

In conclusion, one can say that transistors ushered in the digital age by overcoming limits imposed by vacuum tube technology.

It can be said that without the transistor, life, as we know it today, would be a fantasy.

Perhaps, the once novel and praised transistor may just be the component that is holding us from delving into a new technological revolution and surviving the next era.

With Moore’s law predicted to come to an end in the following years (see Figure 3), researchers from UC San Diego have developed alternatives to transistors in the form of enhanced nanosized vacuum tubes which may scale speed, wavelength and power in the future.[7],[8]

Figure 3: Graph showing the processing power of transistors plateauing and Moore’s Law coming to an end by Research Gate