While human tissues are mostly soft,wet and bioactive; machines are commonly hard,dry and biologically inert.Bridging human-machine interfaces is of imminent importance in addressing grand challenges in health,security,sustainability and joy of living faced by our society in the 21st century.However,designing human-machine interfaces is extremely challenging,due to the fundamentally contradictory properties of human and machine.At MIT SAMs Lab,we propose to use tough bioactive hydrogels to bridge human-machine interfaces.