In this paper a novel L-shape microcantilever that is more sensitive in compare of traditional rectangular microcantilever is proposed. In traditional microcantilever surface stress sensor a slight momentum is induced by distributed area stress lead to a slight deformation. In contrast, the proposed sensor substitution the slight momentum with concentrated point force in lateral direction on the tip of the microcantilever. This lead to, mechanically amplifies of the influence of area stress and more displacement. In addition, it has been theoretically proved that proposed microcantilever sensor with same lateral area in compare with traditional microcantilever surface stress sensor can be 2 to 100 orders more sensitive. The proposed L-shape microcantilever configuration of sensor could be incorporated in most of the microfabrication processes. However in this paper we use a low cost fabrication method based on polymeric microcantilever with metal piezoresistive detection.