how things are built within our bodies?

Why our bodies can regrow and repair themselves,

and how we can pass on genes

from one generation to the next?

Yet, none of our man-made objects have these traits;

they're simply thrown away when they break

and they definitely can't reproduce.

The answer lies in something called self assembly.

Self assembly is a system where unordered parts

come together in an organized structure,

completely on their own.

This means that a pile of parts on your desk should,

in theory, be able to move around on their own,

find one another,

and build something useful.

This seems impossible,

like Transformers

or the Sandman,

but it's exactly how our bodies are built,

how our immune system works,

and why we can reproduce.

Self assembly is the factory and copy machines within our bodies

that make proteins fold and DNA replicate.

It's a process that not only happens

in the biological and chemical world,

but is a phenomenon that can be seen from magnets

to snowflakes,

robotics,

social networks,

the formations of cities and galaxies,

to name just a few.

In biology and chemistry,

self assembly is everywhere,

from atomic interactions,

cellular replication

to DNA, RNA, and protein folding.

Proteins are like bicycle chains

with sequences of amino acid links.

They self assemble into 3-D structures

because of the interaction

between the amino acids along the chain,

as well as the relationship

between the chain and the environment.

These forces make the flexible chain

fold into a 3-D shape

that governs the function in the protein.

Viruses, on the other hand, are like soccer balls.

They're made up of a series of sub-units with specific shapes.

Those shapes have attraction to one another,

so they fit together in precise ways.

Image you want to build a perfect sphere.

It turns out that making a precise sphere

through traditional means is actually quite difficult.

Alternatively, you could try to self assemble the sphere.

One way would be to inflate the sphere

like a bubble or a balloon.

Another option would be to create many identical pieces

that would come together to make a perfect sphere.

You could try to put the pieces together one-by-one,

but it might take a long time

and you would still have human errors.

Instead you could design a connection

between the components like magnets

and dump them into a container.

When you shook the container,

all the parts would find one another

and build the sphere for you.

Self assembly is being used as a new design,

science,

and engineering tool

for making the next generation of technologies

easier to build,

more adaptive,

and less reliant on fossil fuels.

Scientists are now making molecular microchips for computers

where small, molecular elements are given

the right conditions to form themselves into organized pathways.

Similarly, we can now use self assembly

as a way to make 3-D structures with DNA,

like capsules that could deliver drugs inside the body,

releasing them only if certain conditions are met.

Soon, self assembly will be used for larger applications,

where materials can repair themselves,

water pipes can reconfigure on demand,

buildings can adapt on their own

to environment or dynamic loading,

and space structures can self assemble without humans.

Imagine if our factories were more like organisms or brains

and our construction sites were like gardens

that grow and adapt independently.

The possibilities are endless

and it's now up to us

to design a better world through self assembly.