A hydro-thermophoretic trap for microparticles near a gold-coated substrate

Nalupurackal, Gokul; Gunaseelan, M.; Roy, Srestha; Lokesh, Muruga; Kumar, S. Sunil; Vaippully, Rahul; Singh, Rajesh; Roy, Basudev

doi:10.1039/d2sm00627h

Cited by 15 publications

(10 citation statements)

References 53 publications

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“…It is also observed that the particle predominantly emits in a back-scattered direction (−z-direction, see the schematic in figure 3) and self-propels in the opposite direction due to the temperature gradient [35]. This absorption-induced motion can be thought to be an 'active' self-thermophoretic motion inside the optical trap with the tendency of the particle to move from hotter to colder region [40,41]. This will cause the particle to have a complex flow profile with a propulsion velocity, v which is given by [42,43]…”

Section: Theorymentioning

confidence: 98%

Towards Stirling engine using an optically confined particle subjected to asymmetric temperature profile

et al. 2023

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The realization of microscopic heat engines has gained a surge of research interest in statistical physics, soft matter, and biological physics. A typical microscopic heat engine employs a colloidal particle trapped in a confining potential, which is modulated in time to mimic the cycle operations. Here, we use a lanthanide-doped upconverting particle (UCP) suspended in a passive aqueous bath, which is highly absorptive at 975 nm and converts NIR photons to visible, as the working substance of the engine. When a single UCP is optically trapped with a 975 nm laser, it behaves like an active particle by executing motion subjected to an asymmetric temperature profile along the direction of propagation of the laser. The strong absorption of 975 nm light by the particle introduces a temperature gradient and results in significant thermophoretic diffusion along the temperature gradient. However, the activity of the particle vanishes when the trapping wavelength is switched to 1064 nm. We carefully regulate the wavelength-dependent activity of the particle to engineer all four cycles of a Stirling engine by using a combination of 1064 nm and 975 nm wavelengths. Since the motion of the particle is stochastic, the work done on the particle due to the stiffness modulation per cycle is random. We provide statistical estimation for this work averaged over 5 cycles which can be extended towards several cycles to make a Stirling engine. Our experiment proposes a robust set-up to systematically harness temperature which is a crucial factor behind building microscopic engines.

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Section: Theorymentioning

confidence: 98%

Towards Stirling engine using an optically confined particle subjected to asymmetric temperature profile

et al. 2023

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“…A basic hydrothermal method [32] is followed to prepare the Fe-doped NaYF 4 :Yb,Er upconverting particles [21,28]. To prepare 15 at% Fe doped NaYF 4 :Yb,Er (Fe-15 NYF), 0.126 M yttrium nitrate (Y(NO 3 ) 3 ,63 at% of Y) and 0.3 M of sodium citrate (Na 3 C 6 H 5 O 7 ) were mixed with 14 ml of water by vigorous stirring for 10 min.…”

Section: Preparation Of Fe-doped Upconverting Particlesmentioning

confidence: 99%

“…The conventional magnetic hyperthermia technique employs alternating magnetic fields with frequencies in the order of hundreds of kilo-Hertz [24,25]. The precise control over the translations [26][27][28] and rotations [29][30][31],…”

Section: Introductionmentioning

confidence: 99%

Facets of optically and magnetically induced heating in ferromagnetically doped-NaYF₄ particles

et al. 2023

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Upconverting particles like Yb and Er-doped NaYF$_4$ are known to heat up after illumination with light at pump wavelength due to inefficient upconversion processes. Here we show that NaYF$_4$ particles which have been co-doped not only with Yb and Er but also Fe improves the photothermal conversion efficiency. In addition, we show for the first time that alternating magnetic fields also heat up the ferromagnetic particles. Thereafter we show that a combination of optical and magnetic stimuli significantly increases the heat generated by the particles.

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“…In the past, people have demonstrated the indirect trapping of micro-objects by the controlled generation of pressure-driven fluidic environments or by employing potential energy landscapes and force fields generated by the temperature distributions in the particle-fluid neighborhood [ 21 – 23 ]. One such promising approach involves the use of hydro-thermophoretic traps [ 24 ], which can be used to trap and manipulate microparticles using a combination of fluid flow and temperature gradients.…”

Section: Introductionmentioning

confidence: 99%

“…In this study, we demonstrate the controlled, continuous rotation of a microparticle in roll sense, while being confined in a hydro-thermophoretic trap [ 24 ]. It is well known that heating a gold substrate can initiate the thermoplasmonic fluid flows, and also the temperature gradient on the same substrate can cause thermophoretic diffusion of the particle simultaneously [ 23 , 24 , 42 ].…”

Section: Introductionmentioning

confidence: 99%

Controlled roll rotation of a microparticle in a hydro-thermophoretic trap

Nalupurackal,

Panja,

Chakraborty

et al. 2023

Phys. Rev. Research

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In recent years, there has been a growing interest in controlling the motion of microparticles inside and outside a focused laser beam. A hydro-thermophoretic trap was recently reported [Nalupurackal et al ., Soft Matter 18 , 6825 (2022) ], which can trap and manipulate microparticles and living cells outside a laser beam. Briefly, a hydro-thermophoretic trap works by the competition between thermoplasmonic flows due to laser heating of a substrate and thermophoresis away from the hotspot of the laser. Here, we extend that work to demonstrate the controlled roll rotation of a microparticle in a hydro-thermophoretic trap using experiments and theory. We experimentally measure the roll angular velocity of the trapped particle. We predict this roll rotation from theoretical computation of the fluid flow. The expression for the angular velocity fits the experimental data. Our method has potential applications in microrheology by employing a different mode of rotation.

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A hydro-thermophoretic trap for microparticles near a gold-coated substrate

Abstract: Optical tweezers have revolutionised micromanipulation from physics and biology to material science.

Cited by 15 publications

References 53 publications

Towards Stirling engine using an optically confined particle subjected to asymmetric temperature profile

Towards Stirling engine using an optically confined particle subjected to asymmetric temperature profile

Facets of optically and magnetically induced heating in ferromagnetically doped-NaYF₄ particles

Controlled roll rotation of a microparticle in a hydro-thermophoretic trap

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A hydro-thermophoretic trap for microparticles near a gold-coated substrate

Abstract: Optical tweezers have revolutionised micromanipulation from physics and biology to material science.

Cited by 15 publications

References 53 publications

Towards Stirling engine using an optically confined particle subjected to asymmetric temperature profile

Towards Stirling engine using an optically confined particle subjected to asymmetric temperature profile

Facets of optically and magnetically induced heating in ferromagnetically doped-NaYF4 particles

Controlled roll rotation of a microparticle in a hydro-thermophoretic trap

Contact Info

Product

Resources

About

Facets of optically and magnetically induced heating in ferromagnetically doped-NaYF₄ particles