ENRICHING SOCIETY
MAGNETIC FIELDS FOREVER
Signals sent through the body could be the future of wireless .
BY LIEZEL LABIOS , M . S . ’ 10 , PH . D . ’ 12
PATRICK MERCIER , co-director of the Center for Wearable Sensors and affiliate of the Center for Wireless Communications
Signal losses were as much as 10 million times lower than those experienced using Bluetooth .
JUST WHEN BLUETOOTH looked like the ticket to a wireless lifestyle , the power of magnets could make it a thing of the past .
Electrical engineers at UC San Diego recently demonstrated a technique that sends low-power magnetic fields through the human body , proving a concept that could one day enable better communication between wearable gadgets , such as a smart watch or fitness wristband .
The technology came from the lab of Professor Patrick Mercier , co-director of the Center for Wearable Sensors and affiliate of the Center for Wireless Communications . Mercier says the method could yield a lower power and more secure alternative to current Bluetooth wireless technology .
Most mobile and wearable devices transmit information wirelessly using Bluetooth radios , which work well when communicating over short distances — until a body stands in the way . Since Bluetooth radio signals don ’ t travel easily through biological tissues , they require a battery-draining power boost to overcome the obstruction . On the other hand , magnetic fields travel freely through biological tissues , allowing signals to be communicated with little interference .
To demonstrate magnetic field human body communication , Mercier and his team wrapped insulated coils of copper wire around the head , arms and legs of one of their lab members . They then ran an electric current through the coils to produce magnetic fields and measured how well magnetic signals transmitted from one part of the body to another : arm to arm , arm to head and arm to leg . They found that the signal losses were as much as 10 million times lower than those using Bluetooth .
“ This technique will allow us to build much lower power wearable devices ,” says Mercier , who also believes that magnetic communication through the body could provide more security than Bluetooth networks , which are vulnerable to hacking because they transmit data over the air .
For those worried about potential health risks associated with passing magnetic signals through their bodies , Mercier also points out that the technique transmits signals much weaker than those produced by the Earth ’ s natural magnetic field .
The work is still a proof-of-concept demonstration , yet researchers envision developing the technology for applications such as wireless sensor networks that could one day allow for full-body health monitoring .
12 TRITON | WINTER 2016