Lieber's contributions to the rational growth, characterization, and applications of a range of functional nanoscale materials and heterostructures have provided concepts central to the
bottom-up paradigm of nanoscience. These include rational synthesis of functional
nanowire building blocks, characterization of these materials, and demonstration of their application in areas ranging from electronics, computing, photonics, and energy science to biology and medicine. and outlined a general method for the first controlled synthesis of free-standing single-crystal semiconductor
nanowires, providing the groundwork for predictable growth of nanowires of virtually any elements and compounds in the periodic table. He proposed and demonstrated a general concept for the growth of nanoscale axial heterostructures and the growth of nanowire superlattices with new photonic and electronic properties, the basis of intensive efforts today in nanowire photonics and electronics.
Nanostructure characterization. Lieber developed applications of
scanning probe microscopies that could provide direct experimental measurement of the electrical and mechanical properties of individual
carbon nanotubes and nanowires. This work showed that semiconductor nanowires with controlled electrical properties can be synthesized, providing electronically tunable functional nanoscale building blocks for device assembly. Additionally, Lieber invented chemical force microscopy to characterize the chemical properties of materials surfaces with nanometer resolution.
Nanoelectronics and nanophotonics. Lieber has used quantum-confined core/shell nanowire heterostructures to demonstrate
ballistic transport, the superconducting proximity effect, and quantum transport. Other examples of functional nanoscale electronic and optoelectronic devices include nanoscale electrically driven lasers using single nanowires as active nanoscale cavities, carbon nanotube nanotweezers, nanotube-based ultrahigh-density electromechanical memory, an all-inorganic fully integrated nanoscale photovoltaic cell and functional logic devices and simple computational circuits using assembled semiconductor nanowires. These concepts led to the integration of nanowires on the
Intel roadmap, and their current top-down implementation of these structures.
Nanostructure assembly and computing. Lieber has originated a number of approaches for parallel and scalable of assembly of nanowire and nanotube building blocks. The development of fluidic-directed assembly and subsequent large-scale assembly of electrically addressable parallel and crossed nanowire arrays was cited as one of the Breakthroughs of 2001 by
Science. He also developed a lithography-free approach to bridging the macro-to-nano scale gap using modulation-doped semiconductor nanowires. Lieber recently introduced the assembly concept "nanocombing", to create a programmable nanowire logic tile and the first stand-alone nanocomputer.
Nanoelectronics for biology and medicine. Lieber demonstrated the first direct electrical detection of proteins, selective electrical sensing of individual viruses and multiplexed detection of cancer marker proteins and tumor enzyme activity. More recently, Lieber demonstrated a general approach to overcome the
Debye screening that makes these measurements challenging in physiological conditions, overcoming the
limitations of sensing with silicon nanowire field-effect devices and opening the way to their use in diagnostic healthcare applications. Lieber has also developed nanoelectronic devices for cell/tissue
electrophysiology, showing that electrical activity and action potential propagation can be recorded from cultured cardiac cells with high resolution. Most recently, Lieber realized 3D nanoscale transistors in which the active transistor is separated from the connections to the outside world. His nanotechnology-enabled 3D cellular probes have shown point-like resolution in detection of single-molecules, intracellular function and even photons.
Nanoelectronics and brain science. The development of nanoelectronics-enabled cellular tools underpins Lieber's views on transforming electrical recording and modulation of neuronal activity in brain science. Examples of this work include the integration of arrays of nanowire transistors with neurons at the scale that the brain is wired biologically, mapping functional activity in acute brain slices with high spatiotemporal resolution and a 3D structure capable of interfacing with complex neural networks. He developed macroporous 3D sensor arrays and synthetic tissue scaffold to mimic the structure of natural tissue, and for the first time generated synthetic tissues that can be innervated in 3D, showing that it is possible to produce interpenetrating 3D electronic-neural networks following cell culture. Lieber's current work focuses on integrating electronics in a minimally/non-invasive manner within the central nervous system. Most recently, he has demonstrated that this macroporous electronics can be injected by syringe to position devices in a chosen region of the brain. Chronic histology and multiplexed recording studies demonstrate minimal immune response and noninvasive integration of the injectable electronics with neuronal circuitry. Reduced scarring may explain the mesh electronics' demonstrated recording stability on time scales of up to a year. This concept of electronics integration with the brain as a nanotechnological tool potentially capable of treating neurological and neurodegenerative diseases, stroke and traumatic injury has drawn attention from a number of media sources.
Scientific American named injectable electronics one of 2015's top ten world changing ideas.
Chemical & Engineering News called it "the most notable chemistry research advance of 2015". == Criminal conviction ==