Micro-optomechanical Sensor and Fabrication Method Thereof

A sensor system comprising:

• at least one micro-optomechanical sensor comprising:
• a surface comprising a cavity,
• a fluidic channel on the surface connected to the cavity, wherein the fluidic channel is configured to transport a fluid sample to the cavity,
• a cantilever on the surface being laterally extended inside the cavity, wherein at least one side of the cantilever is configured to be in contact with the fluid sample inside the cavity, and
• an optical waveguide on the surface being extended to the cantilever, wherein the optical waveguide is configured to couple out a light signal from the cantilever in order to optically transduce a mechanical vibration of the cantilever;
• at least one light source optically coupled to the optical waveguide of the at least one micro-optomechanical sensor, wherein the at least one light source is configured to generate the light signal for one or more optical waveguides of the at least one micro-optomechanical sensor;
• and
• a processing device optically coupled to the at least one micro-optomechanical sensor, wherein the processing device is configured to receive the light signal coupled out from each of the optical waveguides of the at least one micro-optomechanical sensor and further to optically transduce the mechanical vibration of one or more cantilevers of the at least one micro-optomechanical sensor.

A method for fabricating a micro-optomechanical sensor on a silicon-on-insulator (SOI) wafer comprising a dielectric layer in between a top silicon layer and a bottom silicon layer, the method comprising:

• defining a length of a cantilever and a length of a cavity on the SOI wafer;
• processing an optical waveguide on the top silicon layer, wherein the optical waveguide is extended over the length of the cantilever;
• processing a first etched groove at an edge of the length of the cantilever within the length of the cavity by etching the top silicon layer, the dielectric layer, and partially the bottom silicon layer from the top silicon layer side;
• processing a second etched groove corresponding to the length of the cavity by etching the bottom silicon layer and the dielectric layer from the bottom silicon layer side, thereby forming the cavity in the bottom silicon layer and the cantilever on the top silicon layer laterally extended inside the cavity;
• bonding a substrate on the bottom silicon layer at least encompassing the cavity from the bottom silicon layer side;
• and
• processing a fluidic channel on the top silicon layer from the top silicon layer side.