The following sources were cited in SAP Digital Futures Issue 15 Computing After Silicon

Graphene circuits will shrink to 5 nanometers — 2,000 times smaller than a human hair.
Cade Metz, “IBM’s New Carbon Nanotubes Could Move Chips Beyond Silicon,” WIRED, October 1, 2015,

Quantum computers will be exponentially faster than those we now use.
“Watch: Quantum Computing Explained in Less Than 2 Minutes,” Science Alert, October 18, 2015,

Swedish scientists have built a computer from nanoscopic protein particles.
Using nanotechnology to create parallel computers,” Lund University News and Press Releases. February 2, 2016,

A teaspoon of synthetic DNA could store all the data in the world.
Jacob Aron,Glassed-in DNA makes the ultimate time capsule,” New Scientist, February 11, 2015, 

Passive Wi-Fi uses 10,000 times less power than 802.11a/b/g/n
Mark Harris, “Power from the Air”, 10 Breakthrough Technologies 2016, MIT Technology Review, accessed June 22, 2016,