New Scientist - USA (2022-06-04)

4 June 2022 | New Scientist | 23

Technology

A QUANTUM network can teleport

information between unconnected

nodes – an important step towards

building a secure quantum internet.

Objects that share a quantum

entanglement have linked

properties. This is central to ideas

for a quantum internet. One idea

is to build a network of connected

quantum bits, or qubits, that are

entangled with qubits elsewhere

in the network rather than with

their direct, neighbouring nodes.

Ronald Hanson at Delft University

of Technology in the Netherlands

and his team have built a simple

network containing a number of

diamond-based qubits arranged

into three nodes, dubbed Alice, Bob

and Charlie. There was no direct

connection between Alice and

Charlie, only an indirect link each

shared with Bob. But Alice and

Charlie were quantum entangled.

When Charlie’s quantum state

was changed, Alice’s also changed,

meaning information “teleported”

across Bob rather than passing

through it (Nature, doi.org/gp7gfx).

A quantum internet network

wouldn’t be speedier despite its

apparent instant exchange of data

because users must also link up via

non-quantum communication. But

it would offer eavesdropping-proof

communication. Alex Wilkins

‘Teleportation’ achieved in

miniature quantum network

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British butterflies

are under threat

More than two-fifths

of butterfly species in

Great Britain are at risk of

extinction. Four species

out of the 62 assessed by

the UK charity Butterfly

Conservation are already

regionally extinct, and

24 of the remaining

58 are classed as

either endangered or

vulnerable to being lost

(Insect Conservation and

Diversity, doi.org/hwjk).

Richest homes have

higher wildfire risk

The most valuable homes

in the western US are

70 per cent more likely

to be at high risk from

wildfires than median-

valued properties. High-

income, white and elderly

communities are also

disproportionately at risk

(Environmental Research

Letters, doi.org/gp7kc9).

Lake Erie pollution

could get worse

Efforts to curb algal blooms

in Lake Erie may make the

water more toxic. The lake

is on the US-Canada border

and both nations have

focused on phosphorus

run-off from farms, but

if nitrogen isn’t reduced

as well, toxins in the

lake could actually rise

(Science, doi.org/gp7nxt).

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Robotics

A TINY robot with a soft, flexible

body and spiky feet can climb the

moist, slippery inner walls of the

lungs and gut, where it could one

day deliver drugs.

The new “millirobot” is a few

millimetres long and has feet that

stick to tissue surfaces without

losing grip. The robot resists being

dislodged by jarring movements

and can cling to a surface as liquids

are flushed over it in a similar way

to movement of fluids associated

with breathing and digestion.

The device, controlled by

magnetism, is “a significant

milestone in soft robotics”,

says team member Metin Sitti

at the Max Planck Institute for

Intelligent Systems in Germany.

The robot has two spiked

footpads. Once one is down, the

robot pulls its other foot off the

surface and flips its body over to

take a “step”. When covered with

a layer of chitosan, a substance

found in shrimp shells, the foot’s

“microspikes” created just enough

friction and stickiness for the feet

to latch on to the mucus layer in

pigs’ lungs and digestive tracts –

including the bronchial tubes and

intestines – and then pull away to

take a new step (Science Advances,

DOI: 10.1126/sciadv.abn3431).

Christa Lesté-Lasserre

Micro machine can

climb through body

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Materials

OLD plastic from scrapped cars

can be converted into graphene

by grinding it to dust and zapping

it with high-voltage electricity,

a process that could save large

amounts of plastic from landfill.

Graphene is a form of atom-

thick carbon with a number of

useful electrical and material

properties. James Tour at Rice

University in Texas and his team

have previously found that plastic

could be converted into graphene

via a process called flash joule

heating, where material is heated

to temperatures generally in

excess of 2700°C by passing

high voltages through it.

They have now worked with car

manufacturer Ford to show that

this graphene can be used to make

new parts for cars, and that those

new parts can again be recycled

into fresh graphene.

Tour and his colleagues take

plastic waste that has been

ground down into particles

around a millimetre in diameter.

Their flash joule process turns any

carbon present into graphene,

while also simultaneously

vaporising any other elements

(Communications Engineering,

doi.org/gp7nqs). The yield is

dependent on the amount of

carbon present: high-density

polyethylene contains 86 per cent

carbon by mass, whereas polyvinyl

chloride contains just 38 per cent.

He says certain plastic parts of

cars, such as the bumpers, could

be repeatedly recycled to avoid

waste. An increasing amount of

the plastic used in cars contains

graphene, which adds several

desirable properties, such as

higher strength. Matthew Sparkes

Graphene made

from old bumpers