https://www.newscientist.com/article/2154480-feather-light-artificial-muscles-lift-1000-times-own-weight/

Soft robots are getting better, but greater flexibility has a trade-off as softer materials are often weaker and less resilient than inflexible ones, limiting their use.

But now researchers have created a 2.6-gram “muscle” that can lift a 3-kilogram object – a weight to strength ratio equivalent to a newborn lifting a Land Rover.