Fabrication of microsystems is traditionally achieved with photolithography. However, this fabrication technique can be expensive and non-ideal for integration with microfluidic systems. As such, graphene fabrication is explored as an alternative. This graphene fabrication can be achieved with graphite oxide undergoing optical exposure, using optical disc drives, to impose specified patterns and convert to graphene. This work characterises such a graphene fabrication, and provides fabrication, electrical, microfluidic, and scanning electron microscopy (SEM) characterisations. In the fabrication characterisation, a comparison is performed between traditional photolithography fabrication and the new graphene fabrication. (Graphene fabrication details are also provided.) Here, the minimum achievable feature size is identified and graphene fabrication is found to compare favourably with traditional photolithography fabrication. In the electrical characterisation, the resistivity of graphene is measured as a function of fabrication dose in the optical disc drive and saturation effects are noted. In the microfluidic characterisation, the wetting properties of graphene are shown through an investigation of the contact angle of a microdroplet positioned on a surface that is treated with varying fabrication dose. In the SEM characterisation, the observed effects in the previous characterisations are attributed to chemical or physical effects through measurement of SEM energy dispersive X-ray spectra and SEM images, respectively. Overall, graphene fabrication is revealed to be a viable option for development of microsystems and microfluidics.

Elliptical optofluidic lenses can provide tunable optical parameters in different optical planes. This tunability is achieved through modifications to the aspect ratio (AR). We present an optofluidic lens with a subunit AR. In our experimental analysis, we alter the shape of the microdroplet and observe a 10% reduction in the AR on applying a high voltage across the microdroplet. In our theoretical analysis, we observe improved tunability of focal length, longitudinal spherical aberration, and beam cone angle in the subunit AR regime compared to the superunit AR regime. We ultimately test and characterize the optofluidic lens in an imaging application.

No abstract

Endoscopic devices have limitations through fixed optical properties and narrow field-of-view, which can be overcome with an adaptive compound eye lens. However, fabrication challenges of this adaptive compound eye lens must be overcome.

No abstract