One of my favourite near future technologies are Carbon Nanotube Fibres, which could help turn into reality the dream of space elevators in the next couple of decades. That is because that material would allow the production of ropes that are much lighter than steel ropes yet which can be much longer without snapping under their own weight.
Here’s a current article I found: Tsinghua University in China claims to have developed Carbon Nanotube Fibres which could hold 800 tons - equivalent to 160 elephants - per cubic inch (~2.5 x 2.5 x 2.5 centimetres). According to the article, that corresponds to a Tensile Strenght of 80 Gigapascals. For reference: steel ropes typically have a Tensile Strength of around 2 Gigapascals.
You can produce steel ropes about 10 kilometers (6 miles) long before they snap under their own weight; at 40 times the Tensile Strenght, Carbon Nanotube Fiber ropes could be dangled down 400 kilometers (240 miles) from the International Space Station to the Earth surface without snapping.
Here’s the article:
Here’s the abstract of the scientific paper the article is based on:
Here’s some further reading on the critical constrains of the concept: https://www.newscientist.com/article/2093356-carbon-nanotubes-too-weak-to-get-a-space-elevator-off-the-ground/