Ultrasensitive strain gauge with tunable temperature coefficient of resistivity

In this article, highly sensitive differential pressure sensors based on freestanding membranes of cross-linked gold nanoparticles are demonstrated. The nanoparticle membranes are employed as both diaphragms and resistive transducers. The elasticity and the pronounced resistive strain sensitivity of these nanometer-thin composites enable the fabrication of sensors achieving high sensitivities exceeding 10 −3 mbar −1 while maintaining an overall small membrane area. Furthermore, by combining micro-bulge tests with atomic force microscopy and in situ resistance measurements the membranes' electromechanical responses are studied through precise observation of the concomitant changes of the membranes' topography. The study demonstrates the high potential of free-standing nanoparticle composites for the fabrication of highly sensitive force and pressure sensors and introduces a unique and powerful method for the electromechanical investigation of these materials.

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“…In the latter case they can act as sensing elements for motion, pressure or pulse‐wave monitoring. [ 14–18 ]…”

Section: Introductionmentioning

confidence: 99%

Cross‐Linked Gold Nanoparticle Composite Membranes as Highly Sensitive Pressure Sensors

Schlicke

Kunze²,

Rebber³

et al. 2020

Adv Funct Materials

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“…Metal alloys include manganin and constantin; the latter has been used for over a century in the components of thermocouples. New alloys 5 − 7 have been developed, along with tunable-TCR materials such as metal–polymer composites, 8 − 11 carbon mixtures, 12 and semiconductor composites. 13 − 15 Optical strain sensors that are temperature-independent have also been reported.…”

Section: Introductionmentioning

confidence: 99%

Graphene–Metal Composite Sensors with Near-Zero Temperature Coefficient of Resistance

et al. 2017

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This article describes the design of piezoresistive thin-film sensors based on single-layer graphene decorated with metallic nanoislands. The defining characteristic of these composite thin films is that they can be engineered to exhibit a temperature coefficient of resistance (TCR) that is close to zero. A mechanical sensor with this property is stable against temperature fluctuations of the type encountered during operations in the real world, for example, in a wearable sensor. The metallic nanoislands are grown on graphene through thermal deposition of metals (gold or palladium) at a low nominal thickness. Metallic films exhibit an increase in resistance with temperature (positive TCR), whereas graphene exhibits a decrease in resistance with temperature (negative TCR). By varying the amount of deposition, the morphology of the nanoislands can be tuned such that the TCRs of a metal and graphene cancel out. The quantitative analysis of scanning electron microscope images reveals the importance of the surface coverage of the metal (as opposed to the total mass of the metal deposited). The stability of the sensor to temperature fluctuations that might be encountered in the outdoors is demonstrated by subjecting a wearable pulse sensor to simulated solar irradiation.

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“…The inset shows a continuous sensor having a width of 25 nm and a thickness of 15 nm, which is sufficiently small for cantilevers down to a thickness of 40 nm and a width of 200 nm. The ability to deposit such extremely small-sized strain elements is an essential advantage of FEBID-deposited NTR sensors over other strain-sensing methods based on discontinuous metal layers 29 30 . The small size and thickness enables the fabrication of strain sensors on small AFM cantilevers without greatly affecting their dynamic properties ( Supplementary Fig.…”

Section: Resultsmentioning

confidence: 99%

Direct-write nanoscale printing of nanogranular tunnelling strain sensors for sub-micrometre cantilevers

Ðukić

Winhold²,

Schwalb³

et al. 2016

Nat Commun

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The sensitivity and detection speed of cantilever-based mechanical sensors increases drastically through size reduction. The need for such increased performance for high-speed nanocharacterization and bio-sensing, drives their sub-micrometre miniaturization in a variety of research fields. However, existing detection methods of the cantilever motion do not scale down easily, prohibiting further increase in the sensitivity and detection speed. Here we report a nanomechanical sensor readout based on electron co-tunnelling through a nanogranular metal. The sensors can be deposited with lateral dimensions down to tens of nm, allowing the readout of nanoscale cantilevers without constraints on their size, geometry or material. By modifying the inter-granular tunnel-coupling strength, the sensors' conductivity can be tuned by up to four orders of magnitude, to optimize their performance. We show that the nanoscale printed sensors are functional on 500 nm wide cantilevers and that their sensitivity is suited even for demanding applications such as atomic force microscopy.

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Ultrasensitive strain gauge with tunable temperature coefficient of resistivity

Cited by 19 publications

References 31 publications

Cross‐Linked Gold Nanoparticle Composite Membranes as Highly Sensitive Pressure Sensors

Cross‐Linked Gold Nanoparticle Composite Membranes as Highly Sensitive Pressure Sensors

Graphene–Metal Composite Sensors with Near-Zero Temperature Coefficient of Resistance

Direct-write nanoscale printing of nanogranular tunnelling strain sensors for sub-micrometre cantilevers

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