Abstract: A method of modeling the temperature profile of an IC transistor junction employs an efficient thermal simulation algorithm to implement a design tool for IC design applications. The junction area of a transistor is divided into an odd number of sub-sections of equal size. Each sub-section is modeled as an equivalent circular heat source having an area equal to that of a sub-section. Temperature profiles are determined for each of the equivalent circular heat sources, which are superimposed to provide a total thermal profile for the junction. The method is preferably employed with rectangular-shaped junction areas, and performed with a software-controlled microprocessor. The method may be integrated with an electronic circuit simulation program such as SPICE. The results of the modeling may be used to iteratively modify the component layout on an IC to improve its temperature performance and/or its component density.

Abstract: A method of modeling the temperature profile of an IC transistor junction employs an efficient thermal simulation algorithm to implement a design tool for IC design applications. The junction area of a transistor is divided into an odd number of sub-sections of equal size. Each sub-section is modeled as an equivalent circular heat source having an area equal to that of a sub-section. Temperature profiles are determined for each of the equivalent circular heat sources, which are superimposed to provide a total thermal profile for the junction. The method is preferably employed with rectangular-shaped junction areas, and performed with a software-controlled microprocessor. The method may be integrated with an electronic circuit simulation program such as SPICE. The results of the modeling may be used to iteratively modify the component layout on an IC to improve its temperature performance and/or its component density.

Abstract: A passive structural system includes a structural element which may be subjected to energy which gives rise to vibration in the element. At least one bi-stable sub-structure is coupled to the element. Each bi-stable sub-structure has two stable equilibrium states between which the sub-structure can physically transition when subjected to a sufficient amount of energy which gives rise to vibration in the element, with each bi-stable sub-structure arranged to dissipate at least a portion of the energy and thereby damp the vibration in the structural element when it transitions from one equilibrium state to the other. The passive structural system may also be intentionally mistuned such that when subjected to energy which gives rise to vibration, the vibration energy is substantially confined to localized regions within the system. The bi-stable structures are then located in the localized regions and arranged to dissipate the localized vibration energy.

Abstract: A passive structural system includes a structural element which may be subjected to energy which gives rise to vibration in the element. At least one bi-stable sub-structure is coupled to the element. Each bi-stable sub-structure has two stable equilibrium states between which the sub-structure can physically transition when subjected to a sufficient amount of energy which gives rise to vibration in the element, with each bi-stable sub-structure arranged to dissipate at least a portion of the energy and thereby damp the vibration in the structural element when it transitions from one equilibrium state to the other. The passive structural system may also be intentionally mistuned such that when subjected to energy which gives rise to vibration, the vibration energy is substantially confined to localized regions within the system. The bi-stable structures are then located in the localized regions and arranged to dissipate the localized vibration energy.

Abstract: An electro-osmotic pump includes a pump chamber having a wall fabricated of an electric double layer material, the surface area of the electric double layer material being high relative to the volume of the chamber. An electric potential applied across the material causes a fluid in the chamber to be transported through the wall. A nastic actuator includes the electro-osmotic pump and an actuator chamber, having a variable volume, coupled to the pump chamber. A superabsorbent polymer is disposed in the pump and actuator chambers, such that transport of the fluid into the pump chamber results in absorption of the fluid by the superabsorbent polymer, causing the actuator chamber to increase in volume. When the electric potential is applied across the superabsorbent polymer, the superabsorbent polymer expands, further causing the actuator chamber to increase in volume.

Abstract: A heat spreader for transferring heat from a heat source to a heat sink using a phase change coolant, includes an array of cells, each cell having at least one microporous wick for supporting flows of the coolant in the liquid phase, via capillary action, within the spreader from proximate the heat sink to proximate the source and at least one macroporous wick for supporting flows of the coolant, in the liquid and vapor phase, within the spreader from proximate the source to proximate the heat sink.

Abstract: An electro-osmotic pump includes a pump chamber having a wall fabricated of an electric double layer material, the surface area of the electric double layer material being high relative to the volume of the chamber. An electric potential applied across the material causes a fluid in the chamber to be transported through the wall. A nastic actuator includes the electro-osmotic pump and an actuator chamber, having a variable volume, coupled to the pump chamber. A superabsorbent polymer is disposed in the pump and actuator chambers, such that transport of the fluid into the pump chamber results in absorption of the fluid by the superabsorbent polymer, causing the actuator chamber to increase in volume. When the electric potential is applied across the superabsorbent polymer, the superabsorbent polymer expands, further causing the actuator chamber to increase in volume.

Abstract: Method, apparatus, and computer program products are provided for optimizing a stacking sequence for a composite laminate having multiple zones to reduce the number or length of internal ply edges in the composite laminate with the most design rule compliant sequences. Once the number and location of the zones and the number of plies having different properties required for each zone have been determined for the composite laminate, a master zone is generated. Advantageously, the property of the plies may be fiber orientation, though alternative properties such as material may be considered when determining the number of required plies. The master zone notionally includes the maximum number of plies having a respective property required by any one zone, and the plies of the master zone are sequenced using a predefined series of design rules. The plies of each zone are then arranged based upon the stacking sequence of the master zone.

Abstract: Method, apparatus, and computer program products are provided for optimizing a stacking sequence for a composite laminate having multiple zones to reduce the number or length of internal ply edges in the composite laminate with the most design rule compliant sequences. Once the number and location of the zones and the number of plies having different properties required for each zone have been determined for the composite laminate, a master zone is generated. Advantageously, the property of the plies may be fiber orientation, though alternative properties such as material may be considered when determining the number of required plies. The master zone notionally includes the maximum number of plies having a respective property required by any one zone, and the plies of the master zone are sequenced using a predefined series of design rules. The plies of each zone are then arranged based upon the stacking sequence of the master zone.