Today there are three types of semiconductor memory commonly used in computers. Static RAM is fast, but has a large footprint per cell. Dynamic RAM (DRAM) is fast and has a small footprint (high density) but needs to be periodically refreshed. Flash is slow but permanent and needs high voltage to store data.
A new type of memory has been developed which they claim can replace all three of these types.
https://www.nature.com/articles/s41598-019-45370-1/figures/1
"A new type of computer memory to solve the digital technology energy crisis has been invented and patented by scientists. The device is the realization of the decades long search for a 'Universal Memory' to replace the $100 billion market for Dynamic Random Access Memory (DRAM) and flash drives. It promises to transform daily life with its ultra-low energy consumption, allowing computers which do not need to boot up and which could sleep between key strokes."
https://www.sciencedaily.com/releases/2019/06/190620100015.htm
https://www.nature.com/articles/s41598-019-45370-1