Deep under the surface of a busy university library in central Sydney, robots are controlling a hidden bunker filled with books that once collected dust on the shelf.

The University of Technology's (UTS) library at Ultimo has moved 325,000 library books underground where they are being stored in 12,000 shiny, galvanised steel bins.

But instead of being looked after and managed by librarians, six robotic cranes are doing the job.

The books have been cleaned and fitted with radio frequency tags.

Students can browse for books online and for those who prefer a more traditional approach, there's a "shelf view" which, as the name suggests, allows users to peruse books as they would appear on a shelf.

When a student places an order online, the robot reads the label and collects the items - zooming up and down the five storey steel library.

University Librarian Mal Booth said it means more space for more popular books that are used all the time.

"What we've done is select the least well-used books - although they can be quickly retrieved and we've put them in here," he said.

"That then opens up the library for other purposes.

"We don't have to cram them onto the shelves so that the thinner ones are lost amongst the thicker books.

"We don't have to have the shelves so high so they're easier to reach - particularly for disabled people."

Since opening in July, demand has been steady.

The Library's Access Services Manager, Sharlene Scobie, said the books were still delivered to people in the old-fashioned way - by librarians, pushing trolleys.

"We've had over 600 requests already, they don't have to look for the book, we'll bring it to them - put it on an open shelf so they can just come and collect it," she said.

Millions of books still on the shelf

While technology is king - there is still a quarter of a million books left on the shelves at the university's two libraries.

Mr Booth said he was not worried by the growing popularity of e-books because students prefer to read the real thing and in subjects like art and architecture, only nine per cent of texts had moved online.

Ms Scobie said there were unique items that may never make it onto the internet.

"We have old journals as well in there. We've got maps. We also have microfilm and things like that, newspapers," she said.

"A lot of it's still not digitised so we can still access that and have a look at it."

Unique technology, similar to airports

One academic library in the United States dubbed their electronic system the "bookBot".

But the University of Technology's $28.5 million facility has the more prosaic, yet functional name - the Library Retrieval System.

Subterranean storage systems are more common in European libraries, where space is at a premium, but they are manually operated and often slow.

The books are kept underground in stainless steel containers and are fitted with radio frequency tags. ( ABC News: Nicole Chettle )

There are only two automated library storage systems in Australia. The other is at Macquarie University in Sydney.

But the technology at UTS is unique because: "It's completely underground and it uses radio frequency identification tags on all of the items," said Mr Booth.

The project draws on "mini-load" technology more commonly found in transport and logistics.

"It's used to provide spare parts at airports when they're required quite quickly," Mr Booth explained.

"I've seen them in Woolworths and Coca-Cola Amatil all have facilities that are similar to this."

It even has its own moat to manage an underground deluge.

"They're protected from mould, from dust, from other damage that might come," said Mr Booth.

"Also when we get major storms in Sydney, we expect that we'll get a delayed flooding effect so the moat collects all of that as well."