The miniaturization of wavefront sensors overcomes some of the potential barriers faced by ELTs in implementing large- scale multi-object adaptive optics over large focal surfaces. The Australian Astronomical Observatory is prototyping a compact and lightweight Shack-Hartmann wavefront-sensor designed to be positioned by their Starbug parallel fibre positioning robots. Starbugs perform the critical positioning of optical fibers for the MANIFEST instrument for the GMT. Each wavefront sensor uses a set of polymer bundles to relay the image produced by a microlens array near to the focal plane to a re-imaging module. This allows multiple wavefront sensors to be multiplexed to a single low-noise camera for cost efficiencies per wavefront sensor. The ability to have a large number of wavefronts sensors are likely increase the scientific impact of future ELTs. We illustrate our miniature wavefront sensor concept with a potential design for the GMT.