The present invention provides a system for performing a desired operation in a wellbore. The system contains a downhole tool which includes a mobility platform that is electrically operated to move the downhole tool in the wellbore and an end work device to perform the desired work. The downhole tool also includes an imaging device to provide pictures of the downhole environment. The data from the downhole tool is communicated to a surface computer, which controls the operation of the tool and displays pictures of the tool environment. Novel tactile sensors for use as imaging devices are also provided. In an alternative embodiment the downhole tool is composed of a base unit and a detachable work unit. The work unit includes the mobility platform, imaging device and the end work device. The tool is conveyed into the wellbore by a conveying member. The work unit detaches itself from the base unit, travels to the desired location in the wellbore and performs a predefined operation according to programmed instruction stored in the work unit. The work unit returns to the base unit, where it transfers data relating to the operation and can be recharged for further operation.