Exhibit blog

Nanotechnology: striking a balance between glorification and 'grey goo'

Further reading

Bacteria move around using motors that are smaller than 1,000th the width of a human hair and which rotate faster than a Formula 1 engine. Human cells also contain linear motors which transport cargo and help in cell division. The scientists behind this exhibit investigate how these mini motors work and are building their own.

Minimotors -3-320The crystal structure of the motor protein kinesin shows that it has two identical "feet"(green and blue). The fuel for the motor is ATP (adenosine triphosphate). Fuel molecules are shown in red. Rendered with the UCSF Chimera package.

Due to their small size, molecular motors operate in an environment with very high friction. For humans, this would be equivalent to swimming in treacle. The friction levels lead to challenges and solutions which are removed from our everyday experience yet are happening in our cells all the time.

How it works

Man-made machines and computer chips have been shrinking in size but we are reaching the limits of what can be made using current technology. In order to make smaller machines we will have to start using bottom up construction with molecular components that assemble themselves.

Self-assembled motors already exist in the natural world. There are rotary and linear mini motors which are efficient (~50-100%) and take part in a wide range of processes from movement of organisms to cell division. By understanding how these motors work we can then use them to build and power molecular-scale devices.

We can also try to build our own mini motors. DNA is an ideal material to do this as the interactions between synthetic DNA molecules can be controlled to program how they assemble. Increasingly complex structures have been designed and made by self-assembly including geometric figures, containers and walking devices.

Lead image: A reconstruction of the bacterial flagellar motor from Salmonella enterica using electron microscopy data. The bacterial flagellar motor crosses the cell membrane and uses the difference in proton concentration inside and outside the cell to power its rotation. A long helical tail is attached to the motor and acts like a propeller allowing the bacteria to swim. Credit: Rendered with the UCSF Chimera package.