USM researcher uses nanotechnology to invent high quality varistor

Malaysia has the second highest rate of lighting and thunder occurences (about 280 days a year) after Florida at over 300 days a year.

The imapct results in the destruction of many electrical and electronic equipment and loss of electricity supply. USM researcher, Dr Sharom Mahmud, 46 has improved the varistor technology and succeeded in inventing a high quality varistor which is able to withstand up to 2000 Ampere electrical current without causing any harm to the electrical goods.

This far exceeds the standard 500 Ampere varistors found in most electrical items in our homes. Furthermore, the product is 30 % cheaper at RM 0.70 sen a unit compared to RM1.26 sen a unit for a comparable varistor in the market.

INTRODUCTION
Varistors are semiconductor components that protect electrical equipment from electrical power surges. Currently almost all electrical equipment use varistors for surge protection – it is a must-have product. Each time there is thunderstorm, there are reports of power failure due to power surges – it is a common problem in Malaysia. Most varistors are made from zinc oxide (ZnO) as the main element. The world makes about 3 billion varistors annually.
BACKGROUND
Dr Shahrom started working on varistors 16 years ago when he worked as a varistor engineer at a European-owned factory. He was involved in the improvement of varistor industrial technology. He has produced about half a billion varistors that conformed to world standards. For 7 years, Dr Shahrom has done research to further improve varistor technology with the help from Prof Mat Johar Abdullah. Finally he has produced High Performance Varistors that are proven to outperform international standards. His novel product is recognized by winning a gold medal in PECIPTA 2009. The invention, supported by an incentive grant from USM, is currently being processed for patent filing.
SIGNIFICANCE OF INVENTION TO SOCIETY
High Performance (HP) Varistors are what Malaysia need to solve the severe power surges due to lightning. With about 280 lightning days per year, Malaysia has one of the world’s highest lightning occurence. Many people have reported equipment damage during thunderstorms. HP Varistors can greatly reduce equipment damage due to power surges because they are specially formulated to absorb more electrical energy. They are also cheaper than commercial varistors because 90% of the raw material can be sourced locally and homegrown technology is used. Malaysia will need tens of millions of HP Varistors per year to overcome severe power surges due to lightning. With his decade-long industrial experience, Dr Shahrom has the expertise to build one varistor factory bottom-up.
UNIQUENESS OF THE INVENTION
High Performance Varistors can be produced by controlling at the nano scale. The main ingredient, zinc oxide, possesses several nano morphologies and Dr Shahrom discovered that certain rectangular morphologies tend to give the best energy handling capability for varistors. This nanostructural-electrical correlation is new and many varistor corporations are investigating this fascinating phenomenon. He is also currently attached as a consultation for two zinc oxide companies. State-of-the-art equipment at USM’s NOR Lab and EM Lab are used for this nano research.

This research won the Gold Medal in PECIPTA 2009

RESEARCHER
Dr. Shahrom Mahmud
Senior Lecturer
NanoOptoelectronic Reseach (NOR) Lab
School of Physics
Universiti Sains Malaysia
11800 Pulau Pinang.
Phone: 012-5710976
E-mail: shahromx@usm.my