Despite recent advances in robotic technology, sewer pipe inspection is still limited to conventional approaches that use cable-tethered robots. Such commercially available tethered robots lack autonomy, and their operation must be manually controlled via their tethered cables. Consequently, they can only travel to a certain distance in pipe, cannot access small-diameter pipes, and their deployment incurs high costs for highly skilled operators. In this paper, we introduce a miniaturised mobile robot for pipe inspection. We present an autonomous control strategy for this robot that is effective, stable, and requires only low-computational resources. The robots used here can access pipes as small as 75 mm in diameter. Due to their small size, low carrying capacity, and limited battery supply, our robots can only carry simple sensors, a small processor, and miniature wheel-legs for locomotion. Yet, our control method is able to compensate for these limitations. We demonstrate fully autonomous robot mobility in a sewer pipe network, without any visual aid or power-hungry image processing. The control algorithm allows the robot to correctly recognise each local network configuration, and to make appropriate decisions accordingly. The control strategy was tested using the physical micro robot in a laboratory pipe network. In both simulation and experiment, the robot autonomously and exhaustively explored an unknown pipe network without missing any pipe section while avoiding obstacles. This is a significant advance towards fully autonomous inspection robot systems for sewer pipe networks.

Chikungunya virus (CHIKV) is a single-stranded, positive-sense RNA virus of the Alphavirus genus. CHIKV is an arbovirus, whose spread is mediated by Aedes species mosquitos and is associated with debilitating joint pain and febrile symptoms in infected humans. A lack of vaccine or specific antivirals, combined with increasing global spread, has facilitated the re-emergence of CHIKV in recent years. Our research focuses on the CHIKV encoded non-structural protein-1 (nsP1), which has methyltransferase activity and is essential for virus genome replication. Through a combination of structural, biochemical and reverse genetic approaches, we aim to investigate the relationship between the molecular structure and both canonical and non-canonical functions of nsP1, at different stages of CHIKV replication. We demonstrated that substitution of an in-frame methionine (M24), towards the N-terminal of nsP1, severely inhibits CHIKV replication in a host cell-dependent manner. Specifically, we demonstrated that an M24>A substitution had no significant effect on sub-genomic replicon replication but blocks production of infectious CHIKV virions – suggesting a role in later stages of virus replication, such as packaging or egress, rather than genome replication or translation. Utilising such a reverse genetic approach, analysis of a panel of M24 substitutions has improved our understanding on non-canonical yet essential functions of nsP1 during CHIKV replication. In order to further elucidate both the structural and biochemical basis for the observed mutant phenotypes, we developed a system for bacterial expression and purification of recombinant CHIKV nsP1 and have established crystallography trails, prior to analysis of the molecular structure by X-ray crystallography.