Search

As one of the promising research aspects in BioMEMS, microneedle technology has been widely applied in drug delivery. Compared with the solid microneedles, hollow microneedles can provide continuous delivering drugs. However, the fabrication processes and costs of the hollow microneedles are often complex and high accordingly. We propose a low-cost method to fabricate the hollow metallic microneedles, which contains procedures of using a wet method to etch silicon wafer to get the tapered cavities firstly, filling the tapered cavities with the SU-8 photoresist, developing the SU-8 to pattern the shapes of microneedles, and electroplating one metal in the patterns to form hollow metallic microneedles. According to the method, microneedles with different shape tips that include the triangular pyramids or the rectangular pyramids have been fabricated. In addition, these microneedles have been analysed using a finite element method and tested on artificial skins, which demonstrate the strength of microneedles is sufficient for piercing skins.

Piezoelectric power generator made by microelectromechanical system (MEMS) technology can scavenge power from low-level ambient vibration sources. The developed MEMS power generators are featured with fixed/narrow operation frequency and power output in microwatt level, whereas, the frequency of ambient vibration is floating in some range, and power output is insufficient. In this paper, a power generator array based on thick-film piezoelectric cantilevers is investigated to improve frequency flexibility and power output. Piezoelectric cantilevers array has been designed and fabricated. The cantilevers array can be tuned to the frequency and expanded the excited frequency bandwidth in ambient low frequency vibration. Serial connection among cantilevers of the array is investigated. The prototype generator has a measured performance of [email protected] effective electrical power and 3.93 DC output voltage to resistance load. This device is promising to support networks of ultra-low-power, peer-to-peer, wireless nodes.