IT鈥橲 one of the marks of a classy restaurant that the waiter turns up and discreetly refills your glass the moment you empty it. Now a Japanese electronics company has found a way to guarantee that kind of service鈥攁nd you don鈥檛 have to catch anyone鈥檚 eye.
Developed by Paul Dietz and a team at the Mitsubishi Electric Research Laboratories (MERL) in Cambridge, Massachusetts, the iGlassware system signals staff when you鈥檙e ready for a refill. It uses an adaptation of the radio frequency identification (RFID) tag technology that鈥檚 used to stop people stealing goods from shops.
Each glass in Mitsubishi鈥檚 system is tagged electronically by a microchip linked to a thin radio-frequency coil inside its (dishwasher safe) base. A coating of a clear, conducting material makes the glass behave like a capacitor鈥攁 device that stores electrical charge between two conducting plates separated by an insulator. In this case, the drink is the insulator and the glass鈥檚 base and sides are the conducting plates.
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This is what allows the glass to measure how much you鈥檝e drunk. When you鈥檝e had a few sips and the level of the drink starts to fall, there is less of the glass鈥檚 surface in contact with the insulating liquid. This lowers the capacitance of the glass.
The change in capacitance is read by the microchip, which also stores a digital code unique to that glass. The capacitance and the chip鈥檚 ID are continually transmitted via the coil in the glass鈥檚 base.
The signal is picked up by a receiver set into your table, alerting staff when the glass needs refilling. From the receiver coil, information could be sent back to palmtop devices carried by waiters or to a display behind the bar in a pub.
Dietz built the first prototype of the system using a plastic cup with copper tape wound round the bottom. In the latest version, the receiver coil in the table doubles as a power source for the glass. A radio-frequency signal in the table coil induces a current in the coils in the glasses to keep the glasses powered up, even when they鈥檙e raised a few inches above the table.
The system may sound intrusive, but there鈥檚 a genuine need for it, says Ronald Cole, an expert in hotel and restaurant management at the University of Delaware. Diners like to have their glasses kept topped up, he says, and this system sounds like a promising application of technology to address one of their 鈥減et peeves鈥�. Research shows a high correlation between prompt beverage service and overall customer satisfaction. 鈥淥ur studies show that if there is a long delay between beverage order time and fill and subsequent refill, customers tend to feel less satisfied about the entire dining experience,鈥� Cole says.
The iGlassware system transmits its data on frequencies similar to those used by cellphones. This means that, unlike the security tag readers used in shop doorways, it can鈥檛 interfere with heart pacemakers. On the other hand, if you don鈥檛 learn to say no to the instant refills, you might end up in the cardiac ward anyway.
