Harvesting Vibrations To Power Microsensors

Battery replacement may soon be a thing of the past. Researchers from A*STAR’s Institute of Microelectronics (IME) are tapping into low frequency vibrations, the most abundant and ubiquitous energy source in the surroundings, to power small-scale electronic devices indefinitely.

IME’s energy harvester has the ability to continuously convert the vibrations – across a wide frequency range in different environments – into electricity. This breakthrough presents a green, economical and sustainable long-term solution to eliminate the manual re-charging or replacement of power sources in miniature devices.

2. To use low frequency vibrations efficiently, common attempts focus on expanding the size of the device in order to attain maximum power output, which limit the applications of these energy harvesters. In addition, most reported designs can only operate at one fixed frequency, which significantly reduces the power generation efficiency in practical environments.

3. To address these design challenges, IME researchers have demonstrated an aluminium nitride (AlN) based energy harvester with record-high power density of 1.5 x 10-3 W/cm3 capable of generating electricity equivalent to three commercial implantable batteries[1] over a 10-year period. As an inexorable power supply, the remarkable power density feature translates into massive savings as costs and logistics associated with power source servicing will no longer be relevant.

4. The energy harvester also extends the flexibility of low frequency vibrational sources that can be harvested by offering the widest sampling range of 10th – 100 Hz. The wide sampling range makes it now possible to more productively harness real-world vibrational sources in spite of their irregularity and randomness.

5. Dr Alex Gu, Technical Director of IME’s Sensors and Actuators Microsystems Programme, who conceptualized the energy harvester design, commented, “Our design strategy exploits the coupling effect between the Vortex shedding and Helmholtz resonating in order to enhance the Helmholtz resonating and lower the threshold input pressure. By transferring the low frequency input vibrational energy into a pressurised fluid, the fluid synchronizes the random input vibrations into pre-defined resonance frequencies, thus enabling the full utilization of vibrations from the complete low frequency spectrum.”

6. Professor Dim-Lee Kwong, Executive Director of IME, said, “This breakthrough presents tremendous opportunities to realise a practical, sustainable and efficient energy renewal model with attractive small-form factor, low cost solution for a wide range of applications from implantable medical devices, wireless communication and sensor networks, to other mobile electronics that enable future mobile society.”

Media Contact:

Dr. Shin-Miin SONG
Institute of Microelectronics, A*STAR
DID: (65) 6770-5317
Email: songsm@ime.a-star.edu.sg
About Institute of Microelectronics (IME)
The Institute of Microelectronics (IME) is a research institute of the Science and Engineering Research Council of the Agency for Science, Technology and Research (A*STAR). Positioned to bridge the R&D between academia and industry, IME's mission is to add value to Singapore's semiconductor industry by developing strategic competencies, innovative technologies and intellectual property; enabling enterprises to be technologically competitive; and cultivating a technology talent pool to inject new knowledge to the industry. Its key research areas are in integrated circuits design, advanced packaging, bioelectronics and medical devices, MEMS, nanoelectronics, and photonics. For more information about IME, please visit http://www.ime.a-star.edu.sg.

About the Agency for Science, Technology and Research (A*STAR)

The Agency for Science, Technology and Research (A*STAR) is Singapore's lead public sector agency that fosters world-class scientific research and talent to drive economic growth and transform Singapore into a vibrant knowledge-based and innovation driven economy.

In line with its mission-oriented mandate, A*STAR spearheads research and development in fields that are essential to growing Singapore’s manufacturing sector and catalysing new growth industries. A*STAR supports these economic clusters by providing intellectual, human and industrial capital to its partners in industry.

A*STAR oversees 18 biomedical sciences and physical sciences and engineering research entities, located in Biopolis and Fusionopolis, as well as their vicinity. These two R&D hubs house a bustling and diverse community of local and international research scientists and engineers from A*STAR’s research entities as well as a growing number of corporate laboratories.

[1] Comparison is calculated based on the energy generated from a 10-year usage of the energy harvester against that of a commercial implantable lithium battery with an energy density of 1.05 W.h/cm3 and volume of 2.34 cm3

Associated links
www.a-star.edu.sg/Media/News/Press-Releases/ID/2544/Harvesting-Vibrations-To-Power-Microsensors.aspx