Local interactions between bio-molecules regulate the complex diversity of life. With the development of AFM-based techniques, which allow control and measurement of interaction forces between individual molecules at physiological conditions, a multitude of essential processes such as molecular recognition and protein folding have become accessible at unparalleled resolution and sensitivity. Moreover, the description of molecular devices and machines based on forces rather than thermodynamic variables has provided novel insight into their biological function. This lecture will highlight the advances of the recent years.