Silicon chips now able to bend and fold
"Normally fragile and brittle silicon chips have been made to bend and fold by US scientists"
Published: 27th March 2008 | Source: BBC |
The stretchy circuits could be used to build advanced brain implants, health monitors or smart clothing. The complex circuits consist of concertina-like folds of ultra-thin silicon bonded to sheets of rubber.
Writing in the journal Science, the US researchers say the chip's performance is similar to conventional electronics.
"Silicon microelectronics has been a spectacularly successful technology that has touched virtually every part of our lives," said Professor John Rogers of the University of Illinois at Urbana-Champaign, one of the authors of the paper.
But, he said, the rigid and fragile nature of silicon made it very unattractive for many applications, such as biomedical implants.
"In many cases you'd like to integrate electronics conformably in a variety of ways in the human body - but the human body does not have the shape of a silicon wafer."
Professor Zhenqiang Ma of the University of Wisconsin-Madison, who also works on flexible silicon circuitry, said the new research was an "important step".
"Completely integrated, extremely bendable circuits have been talked about for many years but have not been demonstrated before. This is the first one."
The chips build on previous work by Professor Roger's lab.
In 2005, the team demonstrated a stretchable form of single-crystal silicon.
"The silicon is still rigid and brittle as an intrinsic material but in this accordion bellows geometry, bonded to rubber, the overall structure is stretchable,"
The new work features complete silicon chips, known as integrated circuits (ICs), which can be stretched in two directions and in a more complex fashion.
"In order to do this, we had to figure out how to make the entire circuit in an ultra-thin format," explained Professor Rogers.