The longstanding struggle to get Singaporeans to return their trays at hawker centres and foodcourts has forced one food centre operator to turn to robots to do the job.

Since last month, Koufu at Punggol Plaza has been testing three "smart tray return robots".

These humanoids do what humans would not: with "eyes", sensors and racks in their bodies, they navigate between tables and stop when someone is standing in front of them to return the tray.

When their racks are full, the robots automatically move to the washing area for cleaners to empty them, before moving back to the dining area.

The company said the move is to address the "low rates of customers returning trays", reduce the cleaners' workload and allow them to focus more on cleaning the tables to provide more clean tables for patrons.

WHAT WILL MAKE PEOPLE RETURN THEIR TRAYS?

MAKE RETURN POINTS NEARER If the tray return point is nearby, I'll return my tray. You don't expect me to walk all the way there to return my tray. MS NANCY PHUA, 60, a retiree. CONVENIENCE IS KEY We have to make it convenient for people to return their trays. Tray return facilities must be visible, with signs, and within 10 to 30 feet of walking distance for customers. MR EDWARD D'SILVA, chairman of the Public Hygiene Council. MAKE IT A HABIT Most of us (the hospital staff) are used to returning trays because it has become a habit at the cafeteria. People were initially resistant but over time, if you didn't return your tray, people would remind you too. MS SOON, 40, who works at Yishun Community Hospital. SET AN EXAMPLE As with overall kindness and graciousness, the change and the values have to come from within. This is through education and modelling. If enough (people) begin to show this behaviour (of returning trays) spontaneously, others will follow. DR WILLIAM WAN, general secretary of the Singapore Kindness Movement.

However, the robots, which were designed by local company R Factory, have garnered mixed feedback. Cleaners say the robots have encouraged some people to return their trays. "I like the robots because they make our work easier," said Ms Chin Chie Hoong, 66, who has worked as a cleaner at the foodcourt for six years.

However, one of the robots has been out of action for some time due to "mechanical issues".

Koufu said that six robots will replace the current three by the middle of next month.

Long-time customer Toh Teck Chong, 56, said the novelty factor initially encouraged more people, including children, to return their trays but that effect is wearing off.

"People don't bother to take their trays to the robot once it has moved past them... because there are also cleaners," said the marine surveyor, who has eaten at the centre for the last 10 years.

One cleaner, who declined to be interviewed, was seen using a chair to stop the robot so that he could load trays left on tables into it.

Retiree Nancy Phua, who is in her 60s, saw little use in the machines: "The robot fills up very easily (with trays) and it doesn't move along all the lanes (next to the tables) - like the lane next to the stalls where people are queueing.

"It's better if cleaners come and clear the tables and clean them at the same time because the tables can get dirty."

But ultimately, the habit of returning trays should not be abdicated to cleaners or robots, believes social worker Rani Jayaguru, 37.

Having a tray-return station is still better, she said. "You eat, you clean... it's better than letting the robots do it for you."

Koufu - which operates more than 80 foodcourts, coffeeshops and restaurants here - plans to pilot the robots at seven to 10 of its foodcourts. Four outlets will get the robots next month.

Koufu declined to reveal how much the robots cost.

Other foodcourt operators, such as Kopitiam and Food Republic, are also considering using automated tray-return services. Both operators have tray-return facilities at some of their outlets.

WATCH THE VIDEO

Check out The Smart Tray Return Robots in action at http://str.sg/4YsE.