Magnet attracts attention at international invention awards
Researchers at Polytechnic University have won six prizes at an international exhibition of inventions and ideas.
The winners included a polymer-bonded magnet that can be moulded into any shape. It took a gold medal at the annual Brussels Eureka last month.
The magnet, made from a mixture of polymer and ferrite, is produced in the same way as plastic.
'You can mould this magnet in any shape you desire,' said Wong Yuen-wah, a researcher who took part in the project.
Professor Wong, of the department of applied physics, said a polymer-bonded magnet cost only half the price of a traditional magnetic core and the injection-moulding method allowed faster production.
It could not be used in transformers, but its ability to absorb high-frequency microwaves gave it other applications.
'That is a function that traditional ferrite magnets do not possess,' Professor Wong said. 'It can be used as the shell of mobile phones to screen the user from microwaves.'
Another invention that won a gold medal was a robotic system that helps stroke patients and elderly people perform physiotherapy exercises.
Raymond Tong Kai-yu, who led a group of researchers in the health technology and informatics department on the project, said the PolyJbot rehabilitation system applied forces to the user's body to help them stretch their limbs in a wider arc.
The chair-like system captured the user's intention by monitoring muscle activity using an electrode placed on the skin to compute the degree of force to be applied.
Dr Tong said the robotic system, which costs HK$200,000, could speed up patients' recovery and share the workload of physiotherapists. Stroke patients had begun using the system at PolyU.
Four other inventions - nano-structured photonic fabrics, a technology using nano-material to strengthen metals, an acupressure pen for pain relief and a system using artificial intelligence to optimise warehouse capacity - won two gold medals and two silver medals.
