The Department of Mechanical Engineering of The Hong Kong Polytechnic University (PolyU) has developed a novel bio-inspired nonlinear anti-vibration system that can significantly reduce vibration in various mechanic systems. The innovation far excels existing devices in cost-efficiency and performance reliability, and can have very wide applications.
Inspired by the limb structures of birds and insects in motion vibration control, the novel X-shaped system is of capability to demonstrate nearly "zero response" to any vibration (quasi-zero low dynamic stiffness), but simultaneously of high loading capacity. It also features automatic high damping for strong vibration, and low damping for small vibration (thus preventing high damping's adverse effect on a system's normal functioning during small vibration). These advantages stem from the novel system's nonlinearity - a unique feature lacking in most vibration control systems nowadays which are usually following linear system design. The novel system can therefore be applied very widely in various engineering practices and vibration control devices.
Superb Anti-vibration Device enhances Health Protection for Workers
As a first step in transferring the innovation into daily life benefit, the research team led by Dr Xingjian Jing, Associate Professor of the department, has obtained funding, and facilities and trial support from the construction sector, to embark on research in applying the patented novel system to build an assistive anti-vibration exoskeleton for hand-held jackhammers.
With superb anti-vibration performance, the new device can markedly help prevent hand-arm occupation diseases among construction workers. Using the new device, the vibration at hand/arm in drilling concrete ground can be significantly suppressed to the ideal safety level, compared with many commonly-used jackhammers in the market. The very low cost in manufacturing and maintenance, with great design flexibility for adapting to devices of different sizes and materials, can also enhance its potential popular use. At present, the market price of a common passive control jackhammer is around HK$1,000. It is estimated that PolyU's assistive anti-vibration exoskeleton added to such passive control system will need only an additional HK$1,000 - 2,000, yet with performance far excelling even good-quality active control device that cost about HK$,10,000 - 40,000.
PolyU gains 3 TechConnect Global Innovation Awards
Dr Jing's innovative bio-inspired system is one of the three PolyU innovations having won the TechConnect Global Innovation Awards 2017. It is the first time for a Hong Kong higher education institution receives the awards, along with other global-renowned research institutes (including US NASA, National Labs, Georgia Tech, Princeton Lab, UCLA, Australia National U etc), at the TechConnect World Innovation Conference and Expo, the largest multi-sector summit for supporting the development and commercialization of innovations. The annual event held in the US gathers more than 4,000 technology innovators, ventures, industrial partners and investors from over 70 countries.
Only the top 20% of innovations submitted to TechConnect World will receive awards, with assessment based on the potential positive impact the submitted technology will have on a specific industry sector. PolyU is the only awardee from Hong Kong, and snatches 3 out of the 26 global awards presented to non-US-federal-funded innovations across the world. Another 60 national awards are granted to innovations with US federal funding. The PolyU delegation will present their innovations and receive the awards in mid-May at TechConnect World conference and expo held in Washington DC.
For details of the award, please visit its official website: http://www.
Bio-inspired Nonlinear Passive Anti-Vibration System with Wide Applications
Vibration can be controlled by passive systems, which isolate or mitigate vibration by passive techniques (e.g. rubber pads, mechanical springs, shock absorbers, base isolation), or via active systems, which apply force or energy in an equal and opposite fashion to the vibration force. In general, passive vibration control is most preferred in engineering practices, as its manufacturing, operating and maintenance cost is much lower than active system. It also consumes less energy, and is easier to repair, less complex and thus more reliable. However, the vibration control performance of active systems is much better.
The PolyU novel bio-inspired X-shaped structure possesses all the benefits of the passive and active systems. It has superior nonlinear stiffness and damping characteristics which can suppress vibration transmission and/or absorb vibration energy dramatically in a beneficial nonlinear manner. The system thus has great potential in wide applications, other than applying in vibrating tools, such as jackhammers which is already undergoing research study by Dr Jing's team. Amidst the many spectra the novel system can be applied include robotics, railways, vehicle suspension, precise machines, offshore platforms, marine engineering, aeronautic engineering, and various civil structures like bridges, buildings, etc.