Fabrication of ultra-thin glass sheets and their application to MEMS devices

The miniaturization of chemical and biochemical sensors using microfluidics has several benefits, including small sample consumption, space reduction, and short analysis time. Polymer is typically the most commonly used material for microfluidic chips owing to its simple fabrication process and low cost, but in this review, glass is focused on as a chip material, because glass is both chemically and physically stable. To fully exploit the advantages and overcome the disadvantages of glass, we have developed ultra-thin glass sheets a few micrometers thick and applied to devices such as valves, pumps, sensors, filters, ultra-thin chips, lenses, micro-object controllers, and electric power generators. In this review, these methods and devices are introduced along with some relevant technologies. Ultra-thin glass and related technologies have possibility to be applied not only for microfluidics but also for electronic components or devices such as advanced semiconductor packaging substrates, wearable devices, flexible displays, and solar batteries.