Researchers are working on a cabling system that can provide data transfer speeds several times faster than existing USB connections using an extremely thin polymer cable, in a system that echoes the design path of Thunderbolt.
The research, presented at the IEEE International Solid-State Circuit Conference in February, aims to develop a connection type that offers much better connections than current methods. In part, it is aimed at achieving this by replacing copper wiring with something else.
Copper is commonly used for wires such as USB and HDMI to handle data transfers, but it takes a lot of power to work for high levels of data transfer. “There is a fundamental trade-off between the amount of energy burned and the amount of information exchanged,” said MIT alumni and lead author Jack Holloway.
Although the “increasingly bulky and expensive” copper can be replaced by fiber optic cables, it introduces its own issues. As silicon chips experience problems handling photons, the interconnection between the cable and the computers becomes more difficult to optimize.
According to Holloway, “there are all sorts of expensive and complex integration schemes, but from an economic perspective it is not an excellent solution”, which led developers to create their own version.
A plastic polymer is used by the researchers to combine the benefits of copper and fiber optic channels. This makes it cheaper to manufacture than copper wires, which can be an attractive proposition for cable manufacturers.
The polymer can also use sub-terahertz electromagnetic signals, which are more energy efficient than copper at high data loads. It is believed that this efficiency brings it close to that of optical fiber systems, but is very important with better compatibility with silicon wafers.
Low-cost chips are connected to the polymer line that can generate the high-frequency signals that are powerful enough to transmit directly into the channel. As such, the system is expected to be manufactured according to standard methods, which also makes it cost-effective to manufacture.
The cables themselves can also be extremely thin, with the cross-sectional diameter of the interconnection measuring 0.4 millimeters to a quarter of a millimeter, smaller than typical copper variants.
That small hairy cable can be used to carry data over three different parallel channels, enabling it to achieve a total bandwidth of 105 gigabits per second. If you connect wires together, the cables can reach the terabit per second, while still staying at a reasonable cost.
Echoes of Thunderbolt
The system uses chips on either side of a cable and uses a relatively similar concept to Thunderbolt cables, although it is used with a different channel. In both cases, chips are used in the cable to manage the data fed into the cable on one side and the other, while the connection to the channel itself is also handled.
It seems plausible that such a system could be used for a future Thunderbolt connection, allowing it to go beyond the current upper limit of 40 Gbps.
Another connection with Thunderbolt is research funding. While Thunderbolt was developed by Intel and Apple, the anonymous polymer research was also funded by Intel, along with Raytheon, the Naval Research Laboratory, and the Office of Naval Research.