James Wang

In 2013, the Singapore government announced a plan to build the Cross Island Line, the country’s eighth Mass Rapid Transit train line. Since its release, the proposal has caused ongoing heated debate as it involves going underneath Singapore’s largest remaining reserve: the Central Catchment Nature Reserve. Following extended discussions with environmental groups, the transport authority later stated that they would now consider two route options: a direct alignment running underneath the Central Reserve, and an alternative route that skirts the reserve boundary. The authority warned that the skirting option could increase the construction cost significantly and cost commuters an extra few minutes of travel time. Intriguingly, in contrast to the underground rail project that threatens to further fragment the Central Reserve, another, more visible, repair work is taking place at the edge of the same reserve, aiming to reconnect fragmented habitat through an eco-bridge. Through these two seemingly contrasting yet intimately related case studies in a highly developed city-state, this article explores the complexity and ambivalence of urban movement and its entanglement with development, techonology and urban natures. How are the discourses of urban mobility directed by the desire for ‘velocity’, the politics of invisibility, and a fixation on certainty? What might it mean to reconfigure contemporary practices and ethics towards multispecies movements in an increasingly urbanised environment? Amid the growing expansions of infrastructure and public transportation in Singapore and around the world, often in the name of sustainability and liveability, this article unsettles some taken-for-granted, velocity-charged and human-centred approaches to urban movement and explores the serious need to craft new possibilities for a more inclusive and flourishing urban movement.

© 2014 American Chemical Society.Attempts to apply artificial nano/micromotors for diverse biomedical applications have inspired a variety of strategies for designing motors with diverse propulsion mechanisms and functions. However, existing artificial motors are made exclusively of synthetic materials, which are subject to serious immune attack and clearance upon entering the bloodstream. Herein we report an elegant approach that turns natural red blood cells into functional micromotors with the aid of ultrasound propulsion and magnetic guidance. Iron oxide nanoparticles are loaded into the RBCs, where their asymmetric distribution within the cells results in a net magnetization, thus enabling magnetic alignment and guidance under acoustic propulsion. The RBC motors display efficient guided and prolonged propulsion in various biological fluids, including undiluted whole blood. The stability and functionality of the RBC motors, as well as the tolerability of regular RBCs to the ultrasound operation, are carefully examined. Since the RBC motors preserve the biological and structural features of regular RBCs, these motors possess a wide range of antigenic, transport, and mechanical properties that common synthetic motors cannot achieve and thus hold considerable promise for a number of practical biomedical uses.