Solvent-induced electrochemistry at an electrically asymmetric carbon Janus particle.

Chemical doping through heteroatom substitution is often used to control the Fermi level of semiconductor materials. Doping also occurs when surface adsorbed molecules modify the Fermi level of low dimensional materials such as carbon nanotubes. A gradient in dopant concentration, and hence the chemical potential, across such a material generates usable electrical current.

Colloidal nanoelectronic state machines based on 2D materials for aerosolizable electronics.

A previously unexplored property of two-dimensional electronic materials is their ability to graft electronic functionality onto colloidal particles to access local hydrodynamics in fluids to impart mobility and enter spaces inaccessible to larger electronic systems. Here, we demonstrate the design and fabrication of fully autonomous state machines built onto SU-8 particles powered by a two-dimensional material-based photodiode. The on-board circuit connects a chemiresistor circuit element and a memristor element, enabling the detection and storage of information after aerosolization, hydrodynamic propulsion to targets over 0.

Noble-gas-infused neoprene closed-cell foams achieving ultra-low thermal conductivity fabrics.

Closed-cell foams are widely applied as insulation and essential for the thermal management of protective garments for extreme environments. In this work, we develop and demonstrate a strategy for drastically reducing the thermal conductivity of a flexible, closed-cell polychloroprene foam to 0.031 ± 0.

Ultra-high thermal effusivity materials for resonant ambient thermal energy harvesting.

Materials science has made progress in maximizing or minimizing the thermal conductivity of materials; however, the thermal effusivity-related to the product of conductivity and capacity-has received limited attention, despite its importance in the coupling of thermal energy to the environment. Herein, we design materials that maximize the thermal effusivity by impregnating copper and nickel foams with conformal, chemical-vapor-deposited graphene and octadecane as a phase change material. These materials are ideal for ambient energy harvesting in the form of what we call thermal resonators to generate persistent electrical power from thermal fluctuations over large ranges of frequencies.

Observation of the Marcus Inverted Region of Electron Transfer from Asymmetric Chemical Doping of Pristine (n,m) Single-Walled Carbon Nanotubes.

The concept of electrical energy generation based on asymmetric chemical doping of single-walled carbon nanotube (SWNT) papers is presented. We explore 27 small, organic, electron-acceptor molecules that are shown to tune the output open-circuit voltage (V) across three types of pristine SWNT papers with varying (n,m) chirality distributions. A considerable enhancement in the observed V, from 80 to 440 mV, is observed for SWNT/molecule acceptor pairs that have molecular volume below 120 Å and lowest unoccupied molecular orbital (LUMO) energies centered around -0.

Microscale solid-state thermal diodes enabling ambient temperature thermal circuits for energy applications.

Thermal diodes, or devices that transport thermal energy asymmetrically, analogous to electrical diodes, hold promise for thermal energy harvesting and conservation, as well as for phononics or information processing. The junction of a phase change material and phase invariant material can form a thermal diode; however, there are limited constituent materials available for a given target temperature, particularly near ambient. In this work, we demonstrate that a micro and nanoporous polystyrene foam can house a paraffin-based phase change material, fused to PMMA, to produce mechanically robust, solid-state thermal diodes capable of ambient operation with Young's moduli larger than 11.

Electrical Energy Generation via Reversible Chemical Doping on Carbon Nanotube Fibers.

Chemically modified carbon nanotube fibers enable unique power sources driven entirely by a chemical potential gradient. Electrical current (11.9 μA mg ) and potential (525 mV) are reversibly produced by localized acetonitrile doping under ambient conditions.