Abstract:
Systems and methods of the invention generally relate to altering the functionality of a non-transient electronic device. A container holding an agent is located proximal to a non-tansient electronic device capable of performing at least one function. The agent is capable of rendering the device incapable of performing the at least one function. The container is configured to controllably release the agent to the electronic device in a variety of passive and active eventualities.

Description:
CROSS-REFERENCE RELATED APPLICATIONS 
       [0001]    This application claims the benefit of and priority to Provisional U.S. Patent Application Ser. No. 61/826,371, which was filed on May 22, 2013, the entirety of which is incorporated by reference herein. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention generally relates to transient electronic devices. 
       BACKGROUND INFORMATION 
       [0003]    Modern electronics are often manufactured from electrical conductors (e.g., copper) and semiconductors, primarily silicon. Semiconductor materials such as silicon have enabled construction of the complicated integrated circuits that make up the electronic devices ubiquitous in today&#39;s society. Through established semiconductor fabrication procedures billions of transistors and other electronic components can be integrated into a single microchip. One of the notable properties of silicon, and therefore these electronic devices, is physical durability. 
         [0004]    Biodegradable electronics based on organic materials are known. See, for example, Published U.S. Patent Application No. US 2012/0223293 A1. Such devices use carbon-based electrical semiconductors and/or conductors including various conductive polymers. These organic devices can be lighter and more flexible than traditional inorganic conductors (e.g., copper) and semiconductors (e.g., silicon) but have not reached the performance levels of traditional non-organic materials and cannot be formed using the established techniques and equipment of semiconductor fabrication. Transient devices that require specialized fabrication techniques to create from traditional semiconductors such as silicon and conductor materials such as magnesium also are known. See, for example, U.S. Patent Application No. US 2013/0140649 A1. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention generally relates to making transient devices and systems from traditionally-fabricated non-transient electronic devices. Systems and methods of the invention are directed to controllably altering the functionality of non-transient electronic devices through physical alteration of those devices. One objective of the invention is to take a conventional (i.e., non-transient) commercial off-the-shelf electronic device that is capable of performing at least one function and controllably rendering the device no longer capable of performing that function. Another objective of these systems and methods is to enable multiple modes of initiating the transformation of non-transient electronic devices. These transformations may be active or passive and may be pre-programmed, time dependent, remotely triggered, or in response to an external stimulus (e.g., vibration, light, or temperature changes). 
         [0006]    Systems and methods of the present invention generally comprise a non-transient electronic device such as an electronic memory storage device or microprocessor, an agent capable of rendering the electronic device inoperable, a container to hold the agent, and a means of releasing the agent to the device. The container may be a variety of shapes and sizes and may generally conform to the shape and size of the electronic device. The container is positioned relative to the electronic device so that agent released from the container may physically interact with the electronic device. To this end, the container may for example surround the electronic device, be positioned within a layer above or below the electronic device, or be incorporated into a layer of the electronic device. The system can employ a single container or multiple containers. Containers may be strategically positioned in order to act only on specific portions of the electronic device and thereby alter specific functions of the device while leaving others unaffected. 
         [0007]    The agent can be, for example, a chemical etchant with a low or high pH or an oxidizing agent. The specific agent can be determined to suit the electronic device to which it is paired in the system based on the material properties of the device. For example, the electronic device may comprise a semiconductor material such as silicon and the agent can be a chemical etchant such as hydrofluoric acid. 
         [0008]    Release of the agent may be triggered by, among other things, heat applied to the container or the agent within the container, radiation applied to the container, or mechanical force applied to the container. In some embodiments, the agent or the container may be heated through the application of radiofrequency (RF) energy. In some cases, the system may include a receiver allowing for remote release of the agent, for instance, through remote activation of a transducer to provide RF energy to the container of the agent. Additionally, the container may be constructed of a material designed to degrade over time thereby releasing the agent after a predetermined amount of time. The system may include one or more different sensors which can trigger release of the agent in response to a change in the external environment around the electronic device. 
         [0009]    Methods of the invention relate to constructing a system configured to controllably alter the functionality of non-transient electronic devices through physical alteration of those devices. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  shows an exploded perspective view of a system of the present invention with an ellipse shaped container located in a layer above a non-transient electronic device. 
           [0011]      FIG. 2  shows an exploded perspective view of a system of the present invention with several microcapsule containers located in a layer above a non-transient electronic device. 
           [0012]      FIG. 3  shows a perspective view of a system of the present invention with an ellipse shaped container located within the substrate of a non-transient electronic device. 
           [0013]      FIG. 4  shows a perspective view of a system of the present invention with several microcapsule containers located within the substrate of a non-transient electronic device. 
           [0014]      FIG. 5  shows an exploded perspective view of a system of the present invention with elongated tube-shaped containers above a non-transient electronic device. 
           [0015]      FIG. 6  shows an exploded perspective view of a system of the present invention with elongated tube-shaped containers located in a layer above a non-transient electronic device. 
           [0016]      FIG. 7  shows an exploded perspective view of a system of the present invention with a RF transducer and a sensor. 
           [0017]      FIG. 8  shows an exploded perspective view of a system of the present invention with an actuator and a communication device. 
       
    
    
     DESCRIPTION 
       [0018]    Systems and methods according to the invention relate to changing the functionality of one or more non-transient electronic devices via the controlled release of an agent from one or more containers. A non-transient electronic device of a system according to the invention may be a variety of electronic or microelectronic devices and may comprise inorganic electronic conductors and semiconductors. In certain embodiments, the non-transient electronic device may be a commercial off-the-shelf electronic device. Systems and methods of the invention are primarily directed toward standard electronic commercial off-the-shelf electronic devices. This is in sharp contrast to transient devices that are created specifically to undergo transformation such as the transient devices described in Published U.S. Patent Application No. US 2013/0140649 A1. 
         [0019]    In preferred embodiments, the non-transient electronic device comprises a semiconductor material such as silicon or germanium and a conductor material such as copper. The majority of electronic and microelectronic devices produced and used today are composed of these materials. An advantage of the present invention is its compatibility with existing electronic device technology and production techniques. The current semiconductor device fabrication process is a multiple-step sequence of photolithographic and chemical processing steps during which the device is gradually created on a wafer made of pure semiconducting material, most often silicon. Semiconductor fabrication requires many expensive pieces of equipment and a specialized clean room environment. Deviation from these established fabrication techniques would be expensive and inefficient. The current invention can utilize the existing infrastructure without requiring significant or costly alterations to the established semiconductor fabrication processes. 
         [0020]    A non-transient electronic device according to the invention may be an integrated circuit consisting of millions or billions of microelectronic components such as transistors, capacitors, inductors, resistors, and/or diodes. Examples of non-transient electronic devices include a RAM chip or other volatile memory chip, a microprocessor or other type of central processing unit, or an application specific integrated circuit (ASIC). 
         [0021]    In certain embodiments, the non-transient electronic device may be an integrated circuit with a semiconductor (e.g., silicon) bottom support or substrate and microelectronic components formed above that substrate by the various semiconductor device fabrication process steps. These steps may include doping the semiconductor substrate to change the electrical properties of certain areas, etching the substrate to remove material from selected areas, and depositing material onto the substrate. These processes are often guided by patterns transferred to the substrate through photolithography. 
         [0022]    Non-transient electronic devices of the invention are capable of performing at least one function. That function may be, for example, storing data, processing data or instructions, or sensing a parameter or factor of an environment. As noted earlier, systems and methods of the invention relate to altering the functionality of the non-transient electronic device. Examples of functional changes include rendering the non-transient electronic device completely inoperable; partially inoperable, or unrecognizable and inoperable, enabling new functions, or any combination thereof. In addition to these functional changes, agents of the invention may physically alter the non-transient electronic device to make it unrecognizable or completely dissolved. 
         [0023]    Container or containers of the invention are configured to controllably release at least some of a contained agent to the non-transient electronic device. In systems and methods of the invention, one or more containers are positioned so that an agent released from the one or more containers can physically contact the non-transient electronic device. 
         [0024]      FIG. 1  illustrates an exploded perspective view of a system  100  of the invention. Methods of the invention may be used to construct any of the systems depicted in  FIGS. 1-8  as well as any systems described herein. With reference to the embodiment depicted in  FIG. 1 , a non-transient electronic device  150  comprises multiple discrete or integrated electronic components including transistors  152 , and diodes  151  on a semiconductor bottom support or substrate  120  which are interconnected via channels of a conductor material  155 . Transistors  152  and diodes  151  are shown as examples but any discrete electronic component or integrated circuit element (e.g., resistors, capacitors, transducers, or sensors) may be included in a non-transient electronic device of a system or method of the invention. For ease of illustration the discrete electronic components in  FIGS. 1-8  have been enlarged however systems and methods of the invention also contemplate non-transient electronic devices  150  such as integrated circuits with incorporated transistors and components. In the embodiment shown in  FIG. 1 , a single container  140  in an ellipsoid shape is disposed in a layer  130  positioned above the non-transient electronic device  150 . A cutaway of the layer  130  is shown in  FIG. 1  so that the container  140  within may be seen. The container  140  may be partially or fully contained within a layer  130 .  FIG. 1  further illustrates positioning of a non-transient electronic device  150  and a container  140  including an agent according to a method of the invention. 
         [0025]    Moving to  FIG. 2 , an embodiment of a system  100  of the invention is shown wherein multiple containers  140  of a microspherical shape are disposed within a layer  130  positioned above a non-transient electronic device  150  with a semiconductor substrate  120 . The layer  130  is shown in cutaway view to expose the containers. The containers  140  may be disposed throughout the layer and not visible in  FIG. 2 . As in  FIG. 1 , discrete electronic components including transistors  152  and diodes  151  connected via channels of a conductor material  155  are shown on the surface of the non-transient electronic device  150 . Each container  140  may include the same agent or two or more unique agents. Containers  140  may be configured to release their contained agent individually or in some combination. Release of an agent can thereby be targeted to specific portions of the non-transient electronic device  150  or specific discrete electronic components or integrated circuits therein. Accordingly, functionality of the non-transient electronic device may occur in multiple stages wherein individual functions can be disabled or enabled separately.  FIG. 2  further illustrates positioning of a non-transient electronic device  150  and a container  140  including an agent according to a method of the invention. 
         [0026]      FIG. 3  depicts an embodiment of a system  100  or method of the invention wherein a single, ellipsoid shaped container  400  including an agent is disposed within a bottom support or substrate  400  of a non-transient electronic device  500 . The substrate  400  is shown in cutaway to show the container  400  within. One or more containers may be disposed within a substrate and may take a variety of shapes and sizes.  FIG. 4  illustrates an embodiment wherein multiple microsphere containers  400  are disposed throughout a substrate  200  which is shown in cutaway. Similar to the embodiment depicted in  FIG. 2 , the configuration shown in  FIG. 4  may be used for a targeted release of agent. 
         [0027]      FIGS. 5 and 6  illustrate embodiments of systems and methods of the present invention wherein multiple microtube shaped containers  400  holding one or more agents are positioned above a non-transient electronic device. As shown in  FIGS. 5 and 6 , different containers may be positioned above specific areas or components of the non-transient electronic device  500  including discrete electronic components such as transducers  502  or diodes  501  in order to enable targeted release of an agent as described earlier. 
         [0028]    Containers may be a variety of shapes and sizes. In certain embodiments a container may surround the electronic device. The size and shape of a container, will depend on the non-transient electronic device in the application. For example, a container, may generally conform in shape and size to the non-transient electronic device. Alternatively and as noted above, one or more containers may be configured to release an agent only to a portion of a non-transient electronic device. For example, in embodiments wherein some functions of the non-transient electronic device are disabled while others are left intact or enabled, the container may be sized, shaped, and positioned so that the released agent will only target and effect the specific area of the device associated with the function to be altered. Systems and methods of the invention may also utilize a combination of containers of various shapes and sizes. 
         [0029]    The containers are constructed of one or more materials that are suitable to both contain the agent and release the agent. That is, each of the containers must be constructed and configured to be chemically stable to the contained agent for at least some period of time, such that the agent contained therein is not released until desired. In certain embodiments, the container may be constructed of a material that is reactive with the agent wherein the agent erodes the container over time and is thereby passively released. By manipulating the composition of the agent and the composition and thickness of the material of the container, erosion of the container and subsequent release of the agent can be programmed to occur after a preselected amount of time. Exemplary materials for the container include but are not limited to, polymers, plastics, glass, rubber, metal, or silk. In certain embodiments, the container may be formed as a pocket within a semiconductor material such as silicon wherein the interior surface of the container is the semiconductor material and is configured to be degraded by the agent over a predetermined amount of time so as to controllably release the agent to the rest of the non-transient electronic device as described above. Alternatively, the material of the container may degrade upon exposure to certain wavelengths of radiation or upon exposure to a certain substance such as water. 
         [0030]    In embodiments where the containers are incorporated within the device, the containers may be constructed using the steps of the semiconductor device fabrication process described earlier. In other embodiments, containers may be constructed using techniques well known in the art such as injection molding, casting, or thermoforming. The agent may be encapsulated by the container during the forming process of the container or may be injected or otherwise introduced into the container after formation. 
         [0031]    The agent used in a particular embodiment will be selected to impact the specific non-transient electronic device in the embodiment, or one or more portions thereof, in the desired manner. In certain embodiments, a single agent will be used while in other embodiments multiple agents may be isolated within separate containers. Selection of the agent will depend upon the application and may be based on considerations such as the material properties of the non-transient electronic device, the degree of physical alteration desired as well as user and/or environmental safety. Multiple agents may be used wherein each agent in isolation has no effect on the functionality of the non-transient electronic device but when combined, the agents alter the functionality. Alternatively, one agent may act to neutralize the transformative effects of another agent wherein release of the agents is staggered in order to limit the degree of transformation. Regardless of specific composition, at least one agent in a system or method of the invention acts to destroy or impair some or all of the functional operation of a non-transient electronic device, or to cause it to perform a different function after exposure to the agent. 
         [0032]    An agent used in a system or method of the present invention can be a chemical etchant such as those used in traditional semiconductor fab processes. Chemical etchants work by eroding the surface of the target material, in the case of semiconductor fabrication the target material is a semiconductor material such as silicon. Electronic devices formed from silicon and other semiconductor materials rely on many small electronic circuits integrated onto a single substrate. These circuits may be defined and separated by minute channels in the semiconductor material. Therefore, removal of additional semiconductor material through a process such as etching can disrupt the complicated electronic components of an electronic device. In embodiments utilizing an etchant as an agent, the functionality of a non-transient electronic device may be altered through this process. A chemical etchant agent can have a low pH or a high pH. Various kinds of etchants can be used as an agent including for example, hydrochloric acid (HCl), hydrofluoric acid (HF), dilute HF (such as 51% deionized water and 49% HF), buffered HF (containing NH4F and HF), phosphoric acid, nitric acid, combinations of the foregoing, and others. Some possible high pH chemical etchants include tetramethylammonium hydroxide, alkali metal hydroxides, and strongly basic amines. 
         [0033]    The agent may instead be an oxidant. By oxidizing the semiconductor material the agent may change its electronic properties and thereby disrupt the function of the non-transient electronic device. For example, the oxidized form of silicon, silicon dioxide, is utilized as an insulator in integrated circuits and oxidation of additional portions of silicon within a substrate may serve to disrupt the functionality of a non-transient electronic device. Alternatively, an oxidizing agent may be directed to a conductor material within the non-transient electronic device resulting in altered electrical properties and device function. 
         [0034]    Release of an agent from one or more containers to a non-transient electronic device may be initiated by a variety of methods. In certain embodiments, a system  100  may include a heating mechanism such as a radiofrequency (RF) transducer  600  as shown in  FIG. 7 .  FIG. 7  further illustrates positioning of a non-transient electronic device  150 , multiple containers  140  including one or more agents, a sensor  900  and multiple RF transducers  600  according to methods of the invention. Systems and methods of the invention may include a variety of different sensors configured to sense one or more parameters including but not limited to vibration, light, a change in biological environment, temperature, pressure, electromagnetic radiation, concentration of an analyte, electric or magnetic fields, pH, or voltage. Such sensors  900  may be in communication with an RF transducer  600  as shown in  FIG. 7 , an actuator, or other component which may in turn act on a container to trigger release of an agent and a corresponding functional alteration in the non-transient electronic device. RF energy may be focused on the container or the agent in order to precipitate release of the agent from the container. By heating the agent within a container, pressure may build in the container until the container is ruptured and the agent is released. Alternatively, the container may be constructed of a material configured to degrade when exposed to a certain level of heat wherein the release of the agent from the container may be triggered by RF or other energy directed to the container. 
         [0035]    In certain embodiments, the container may release the agent upon physical manipulation. The container can be constructed of a brittle material such as glass. In such instances, the container may be configured to release the agent when subjected to a threshold external force, such as the non-transient electronic device being dropped or upon attempts to deconstruct or tamper with the non-transient electronic device.  FIG. 8  illustrates a system  100  and method of the invention wherein physical disruption of multiple containers  400  is utilized. The system and method depicted in  FIG. 7  includes multiple actuators  600  configured to rupture multiple containers  400  when activated by a communication device  800  in communication with the actuators. Actuators, transducers, or other devices configured to initiate the release of the agent to the non-transient electronic device may be programmed to activate after a set amount of time or may be remotely activated. Methods and systems of the invention may include a receiver or other communication device  800  as shown in  FIG. 8  whereby release of the agent may be triggered remotely upon receipt of a remote transmission. A communication device  800  may be in communication with an actuator  700  as shown in  FIG. 8 , an RF transducer, or other component which may in turn act on a container to trigger release of an agent and a corresponding functional alteration in the non-transient electronic device. 
         [0036]    Various modifications of the invention and many further embodiments thereof, in addition to those shown and described herein, will become apparent to those skilled in the art from the full contents of this document. The subject matter herein contains important information, exemplification and guidance that can be adapted to the practice of this invention in its various embodiments and equivalents thereof.