Abstract: A sensor for recording bioelectrical signals directly from hairy skin regardless of the amount or density of hair is fabricated using a polymer with an electrically conductive filler. The sensors have a stemmed conical microstructure array (CMSA) on the sensor surface that interfaces with and adheres to the skin between the hairs. The CMSA sensors are fabricated using a viscosity-controlled dip-pull process (VCDP), including dipping a mold into an electrically conductive polymer precursor having a selected viscosity that is optimized for formation of the conical microstructures upon a controlled pulling of the mold from the polymer precursor.

Abstract: Nanomaterial epidermal sensors can be adhered to the skin and worn comfortably and inconspicuously for days to allow for repeated biometric sensing. The nanomaterial epidermal sensors may be comprised of a monolayer of graphene coating a flexible polymer substrate. Various nanomaterial epidermal sensors may be quickly fabricated using a cost-efficient “cut-and-paste” method on transfer paper and can be adhered directly to skin without tape or adhesive, much like a temporary-tattoo. The nanomaterial epidermal sensors may be optically transparent and may be used to measure an electrocardiogram (ECG), an electroencephalogram (EEG) or an electromyogram (EMG) with a signal-to-noise ratio that is comparable to conventional electrodes. In addition, the nanomaterial epidermal sensors may be used to measure other parameters, such as skin temperature or skin hydration.

Abstract: A field effect transistor having a channel that comprises three-dimensional graphene foam. The subject matter of the invention concerns a three dimensional field-effect transistor having a channel based on graphene foam and the use of ionic liquid as a gate. The graphene foam is made of a three-dimensional network of single and double layer graphene that extends in all the three dimensions. Metal contacts on either end of the graphene foam form the drain and source contacts of the transistor.

Abstract: Nanomaterial epidermal sensors can be adhered to the skin and worn comfortably and inconspicuously for days to allow for repeated biometric sensing. The nanomaterial epidermal sensors may be comprised of a monolayer of graphene coating a flexible polymer substrate. Various nanomaterial epidermal sensors may be quickly fabricated using a cost-efficient “cut-and-paste” method on transfer paper and can be adhered directly to skin without tape or adhesive, much like a temporary-tattoo. The nanomaterial epidermal sensors may be optically transparent and may be used to measure an electrocardiogram (ECG), an electroencephalogram (EEG) or an electromyogram (EMG) with a signal-to-noise ratio that is comparable to conventional electrodes. In addition, the nanomaterial epidermal sensors may be used to measure other parameters, such as skin temperature or skin hydration.

Abstract: A field effect transistor having a channel that comprises three-dimensional graphene foam. The subject matter of the invention concerns a three dimensional field-effect transistor having a channel based on graphene foam and the use of ionic liquid as a gate. The graphene foam is made of a three-dimensional network of single and double layer graphene that extends in all the three dimensions. Metal contacts on either end of the graphene foam form the drain and source contacts of the transistor.