NOVELTY - The method comprises: contacting a first bonding surface of a first substrate with a second bonding surface of a second substrate to form an assembly: and compressing the assembly in the presence of an oxidizing atmosphere under suitable conditions to form a bonding layer between the first surface and the second surface, where the conditions comprise application, to the assembly, of an electromagnetic field. The first bonding surface comprises a polarized surface layer. The second bonding surface comprises a hydrophilic surface layer, where the first and second bonding surfaces are different.    USE - The method is useful for bonding substrates that are useful in an implantable medical device and a solar cell (all claimed), where the medical device is a bio-sensor.    ADVANTAGE - The method is capable of economically bonding the substrates with improved bonding characteristics and mechanical strength thus improving reliability, lifetime and performance of the solar cell, eliminating the electrostatic repulsion between the surfaces of the substrates to be bonded, minimizing built-in stress between the bonded substrates, and eliminating the requirement of any physical deposition or plasma/sputtering/dry etching processing to achieve bonding strength.    DETAILED DESCRIPTION - The method comprises: contacting a first bonding surface of a first substrate with a second bonding surface of a second substrate to form an assembly: and compressing the assembly in the presence of an oxidizing atmosphere under suitable conditions to form a bonding layer between the first surface and the second surface, where the conditions comprise application, to the assembly, of an electromagnetic field. The first bonding surface comprises a polarized surface layer. The second bonding surface comprises a hydrophilic surface layer, where the first and second bonding surfaces are different. The applied electromagnetic field comprises a voltage of 10 V. The compressing step is carried out at a pressure of 0.10-0.11 MPa and a temperature of less than 1450 degrees C for 2 hours. The first and second substrates are wafers or beads. The oxidizing atmosphere is air, which has 40-80% of relative humidity. The first substrate and the second surface are essentially flat. The bonding layer has a bonding strength of 10 MPa. The first substrate is a silicon wafer, and the second substrate is a silicate wafer. The first bonding surface is formed by cleaning the silicon wafer with a Herbots-Atluri clean. The second bonding surface is formed by chemical etching followed by chemical oxidation of the silicate wafer.