Dr Joe Shaw, the managing director and CEO of Sydney-based biosensor specialist Ambri (ASX: ABI), has resigned from the company and will return to the US.

He will be replaced at the helm by non-executive director David Cornelius until a new, permanent CEO can be found. Cornelius is on secondment from his position as executive director of Ambri partner Dow Corning's new ventures division.

Shaw, who joined the company almost four years ago, had helped usher in "substantial progress towards commercialisation" of Ambri's biosensor technology, said company chairman Dr John Eady in a statement.

He said Cornelius, with the help of new COO Dr Jonathan Wright, would "provide new and valuable skills and experience needed to lead Ambri through the next phases pf its development."

Shaw said he expected to return to the US at Easter but said he would not comment further at this time. Cornelius was not available for comment by press time.