Conventional pumps are unsuitable for clinical applications requiring chronic implantation in delicate tissues or applications that require precise low-volume fluid control (single nanoliter stroke volumes, negligible dead volumes) and bidirectional flow. Precision medicine requires the identification of an individual’s unique pathology followed by accurate drug delivery to target tissues. Ideally, implantable fluid pumps for this application would have the capacity to offer long-term micro-invasive fluid sampling while also facilitating targeted drug delivery. Existing syringe-based and peristaltic positive displacement pumps have large dead volumes (> 200 nanoliters), and thus cannot deliver or sample extremely small volumes of liquid. Most implantable pumps, moreover, are designed for unidirectional operation and operate at microliter/second flow rates. They also often contain magnetically susceptible materials that are not compatible with common medical imaging modalities such as magnetic resonance imaging (MRI). This invention is a peristaltic pump that is actuated by MRI-compatible materials and is capable of low-volume bidirectional fluid control (single stroke volume < 3 nanoliters, dead volume < 30 nanoliters). This pump can be manufactured in either an implantable or wearable form and can interface with a parenteral implanted probe inserted into the pump’s fluidic channel. This enables acute and chronic micro-invasive withdrawal of small-volume liquid biopsies for diagnostics and delivery of precise drug volumes into a target tissue.