LEAP-HI: Ultra-Low Power Computing: A Disruptive Approach Through a New Integrated Nanomechanics Framework

Carnegie Mellon University, Pittsburgh PA

Investigators

Abstract

Modern society relies on microelectronic computing devices. Performing billions of calculations per second, microprocessors enable the internet, smart phones, laptop computers, cloud computing and digital cameras. Although microprocessors are extremely powerful when it comes to fast computation, they consume a lot of energy. This is because the billions of transistors in microprocessors have become so small that they leak electrical current even when they are off. New generations of powerful computing hardware will require more energy efficient microprocessors. Transistors are solid state switches with no moving parts. This Leading Engineering for America's Prosperity, Health, and Infrastructure (LEAP-HI) award supports fundamental research to replace solid state transistors with nanomechanical switches that can open and close to make and break an electrical contact. These contacts can operate at the speed of computers because of their incredibly small size. Nanomechanical switch contacts are operated with nanonewton forces applied normal to the interface. Though small, the actual points of contact - nanometer-scale asperities - are subject to both high stress and high current density, creating multiple degradation pathways. Metallic materials have been used to make the electrical contacts, but they eventually weld together. The objective of this work is to investigate whether hard conducting oxide coatings on the metals can be used to overcome this adhesion problem. The intellectual merit of this project is in meeting a grand challenge at the intersection of mechanics, tribology and materials development: to develop interfacial systems that not only achieve but maintain extremely low and stable adhesion and electrical contact resistance after billions to trillions of contact cycles with minimal degradation. To accomplish this, the research team will perform density functional theory calculations of oxide conduction mechanisms, and finite element and molecular dynamics modeling of contact stresses. Experimentally, different oxides will be tested using atomic force microscopy. Promising materials systems will be integrated into prototype nanomechanical switches, and their functionality will be tested up to trillions of cycles. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.