Robots have been developed for all kinds of uses – search and rescue robots, helper robots to live with elderly people, medical operating robots. You name it, there’s probably a robot that does it. But what these robots all have in common is that they tend to be hard and inflexible.
Steven Dirven of Massey University is much more interested in soft robotics.
"In New Zealand soft robotics are being used to model organs of the human body and ways we can interact with them.”
Steven’s organ of choice is the oesophagus, and for the past few years he has been developing a prototype swallowing robot.
He says the idea is to model the oesophagus in a biomimetic way, and create a device that food technologists can use to develop new foods for people who have swallowing difficulties.
Steven says that about half of the ‘institutionalised elderly’ have swallowing difficulties.
The swallowing robot mimics the oesophagus of an adult male. It is made of silicon tubing with a diameter of 20 millimetres, and it is 26 centimetres long. There are a range of air chambers around the outside that squeeze the tube and sequentially contract. This simulates the wave-like peristalsis of swallowing.
“What we’re doing is measuring the pressures of how hard it is to transport different foods from the mouth to the human stomach.”
The pressure inside the food and the pressure of the wave is measured using manometry. This is a thin pressure-sensitive tube passed through the oesophagus, and is the same technique used in humans.
The main difference between the humans and robots is that the swallowing robot takes in food at the bottom and moves it to the top. The food moves at speeds of 2-4 centimetres per second.
Steven Dirven began working on the swallowing robot with Peter Xu and his mechatronics team at the University of Auckland. He is now a lecturer in Mechatronics and Robotics at the School of Engineering and Advanced Technology, at Massey University in Albany.