Abstract
An innovative platform was developed for ultrasensitive microsensors based on microcantilevers patterned with crosslinked copolymeric hydrogels. A novel UV free-radical photolithography process was utilized to precisely align and pattern environmentally responsive hydrogels onto silicon microcantilevers, after microcantilevers were fabricated and released. Specifically, a crosslinked poly(methacrylic acid) network containing high amounts of poly(ethylene glycol) dimethacrylate was prepared and investigated. Hydrogels were patterned onto the silicon microcantilevers utilizing a mask aligner to allow for precise positioning. The silicon surface was modified with γ-methacryloxypropyl trimethoxysilane to gain covalent adhesion between the polymer and the silicon. The hydrogels sensed and responded to changes in environmental pH resulting in a variation in surface stress that deflected the microcantilever. The bending response of patterned cantilevers with a change in environmental pH was observed, showing the possibility to construct MEMS/BioMEMS sensors based on microcantilevers patterned with environmentally responsive hydrogels. An extraordinary maximum sensitivity of 1 nm/5 × 10-5 ΔpH was observed, demonstrating the ultrasensitivity of this microsensor platform.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 177-184 |
| Number of pages | 8 |
| Journal | Biomedical microdevices |
| Volume | 5 |
| Issue number | 3 |
| DOIs | |
| State | Published - Sep 2003 |
| Externally published | Yes |
Keywords
- BioMEMS
- Free-radical photopolymerization
- Hydrogel
- MEMS
- Microcantilever
- Micropatterning
- Microsensor
- pH sensor
ASJC Scopus subject areas
- Medicine (miscellaneous)
- Genetics
- General Neuroscience