System and methods for wireless drug delivery on command
A fully integrated small size implantable sensing device is described, which can include a sensor and an electronic circuit to interface with the sensor and communicate with an external device. Various fabrication methods for the sensing device are described, including provision of wells, created using same fabrication technology as the electronic circuit, to contain electrodes of the sensor and corresponding functionalization chemicals. Such implantable sensing device can be used for a variety of electrochemical measuring applications within a living body as well as actuation by injecting a current into the living body.
1. A method for fabricating a miniaturized implantable device:
fabricating an electronic system by monolithically integrating the electronic system on a first face of a substrate, the electronic system comprising an energy storage element adapted to be charged through a wireless communication link;
fabricating a coil by monolithically integrating the coil on the first face of the substrate, the coil being configured to provide the wireless communication link; and
fixating at least one hermetic package, containing a liquid payload, on the first surface of the substrate, a portion of the hermetic package being positioned above the coil,
wherein the energy storage element is configured to provide energy to rupture a seal of the hermetic package, thereby dispensing the liquid payload.
2. The method according to claim 1 , wherein the rupture of the seal is provided by applying heat to the seal.
3. The method according to claim 2 , wherein the heat is provided by injecting current in the coil, the current provided by the energy storage element.
4. The method according the claim 1 , wherein the rupture of the seal is provided by applying internal pressure to the hermetic package.
5. The method according to claim 4 , wherein the internal pressure is provided by gases released through an electrochemical dissociation reaction of an electrolyte solution contained in the hermetic package, energy for the electrochemical dissociation being provided by the energy storage element.
6. The method according to claim 5 , wherein the hermetic package comprises one chamber containing a mixture of the electrolyte solution and the liquid payload.
7. The method according to claim 5 , wherein the hermetic package comprises two separate chambers, a first chamber containing the electrolyte solution and a second chamber containing the liquid payload.
8. The method according to claim 1 , further comprising:
fabricating a plurality of electrodes of an electrochemical sensor by monolithically integrating the plurality of electrodes on the first face of the substrate, the plurality of electrodes being configured to provide electrical interface between the electrochemical sensor of the implantable device and the electronic system.
9. The method according to claim 8 , wherein the fabricating the plurality of electrodes further comprises fabricating the plurality of electrodes on a first metal layer separate from metal layers used to fabricate the electronic system.
10. The method according to claim 8 , wherein the fabricating the plurality of electrodes further comprises creating a plurality of wells in correspondence of the plurality of electrodes.
11. The method according to claim 1 , wherein the energy storage element is a bank of capacitors charged through power extracted from the wireless communication link.
12. The method according to claim 1 , wherein the fabricating of the coil comprises fabricating a plurality of concentric patterns on a first metal layer separate from metal layers used to fabricate the electronic system.