People
STUDENTS:
Juan Manuel Molina (PhD thesis)
As shown in previous experiments, a light field can induce a crystallization transition when the periodicity of the field is carefully selected. Juan Manuel will be exploring different scenarios where the light field could be able to induce non-equilibrium scenarios, including the glass transition but also temporal-dependent light fields. He will be also starting a new project related to the diffusion of active colloids in periodical potentials.
Norma Palmero (PhD thesis in collaboration with Ramón Castañeda)
Norma's project is related with the correlations between particles trapped in harmonic potentials where the solvent is undergoing a critical point transition. She is using holographic optical tweezers to trap two particles in a lutidine/water mixture, but is also using molecular dynamics simulations to understand the phenomena.
Natalia Rincón (Former posdoc, now Associate Professor, DCI, UGTO)
Natalia is currently working in the synthesis of an active system using the lutidine/water mixture, in which the activity is initiated locally by a silica particle partially covered with carbon. The part covered with carbon can absorb light and thus locally increase the temperature, and thus, by using a temperature slightly below the critical point, a local demixing transition is initiated inducing the activity. Depending on the laser power, the grade of activity changes. She will be also analyzing the possibility of inducing flock motion of active particles by using non-hydrodynamic confinement in optical tweezers, or in microfluidic channels with obstacles.
Sol María Hernández (PhD student)
Sol is using a recently developed random walker simulation to mimic the typical situation found in microrheology and explain the short time - intermediate time transition of the MSD. Colloidal particles in complex fluids as polymers or worm like micelles are caged for some time in the free space of the solution. However, the distribution of cages may be quite broad, and typical microrheology experiments perform an ensemble-average.
Ramon Alejandro Castañeda (undergrad social service)
In collaboration with Manuel Escobedo, Ramon is exploring the precision in videmicroscopy-based tracking at different wavelength, trying to define the best parameters to decrease error in tracking.
Victor Herrera Canales (Master student)
Victor is exploring the use of deep learning methods for the prediction of a 2D gel-like structure induced by depletion. Victor is also supporting part of Natalia's project related to the phase separation of lutidine and water.
Daniela Ramirez Bermudez (Master student)
TBD
ALUMNI:
Victor Herrera Canales (undergrad social service), performed a study trying to push the resolution limite of videomicroscopy down to nanometer scale.
Adriana Martínez (undergrad social service), continued Gaby's study of the viscoelastic properties of worm-like micelles. Gaby found a very interesting behavior changing the temperature of the solution. Adriana also analyzed the effects of the viscoelasticity on a hydrodynamic focusing microfluidic channel.
Jaime Albarrán (undergrad social service), studied the 2D structures formed by the aggregation of monomer particles induced by the depletion effect. When polymer or small particles are added to a colloidal suspension, the modification of the osmotic pressure as the depletant is unable to fit between two colloidal particles, induces an attractive force on the particle, giving aggregation. Aggregation also increases the gravitational effect on the particles, and thus form a structure in the glass plate below. Jaime expored different physical parameters in order to correlate them with the structure formed.
Alan García and Emilio Villa explored the random walker simulation in order to simulate several situations or colloidal science interest: confinement due to optical tweezers, unidirectional external fields, harmonic and brownian cages.
Doriana Dorta (University of Panama), Hector Contreras (UASLP), Karim Romero (UASLP), Summer research program 2018. Doriana, Hector and Karim studied the behavior of individual cells (red blood cells) under deformation using Holographic Optical Tweezers. This project was done in collaboration with Beatriz Morales and Francisco Perez, Engineering school, UASLP.
Gabriela Angeles Robles (summer student 2017), currently PhD student at PCI, UASLP. Gaby performed a short microrheologic study of a wormlike micellar system (CTAB-NaSal) using a DLS system and comparing with mechanical rheology experiments.
Daniela Pérez (undergraduate thesis 2018), currently master student at PCI, UASLP. Daniela study the dynamic properties of colloidal particles interacting with a periodic potential. In collaboration with Dr. Ivan Guerrero, we are still working in this project, analyzing the statistics of the jump time distribution using brownian dynamics simulations
Yuridia Selene Posadas García (undergraduate thesis 2016), currently PhD student at PCI, UASLP. Yuri's thesis is named "Manipulation and neuronal growth using optical tweezers". Yuri used an infra-red optical tweezers to manipulate neurons (in collaboration with Alfredo Méndez IFUASLP).
Alejandro Rivera Morán (undergraduate thesis 2016), currently PhD student at Julich, Germany. Alex's thesis is named "Manipulation of anisotropic particles and bacterias using laser-induced external fields". Using a periodical distribution of light Alex is comparing the predictions of a recently developed algorithm for the calculation of the energy landscape of spherical clusters in periodical distributions of light with experimental results.
Jose Ramón Villanueva Valencia (Masters and summer student 2013-2015), currently PhD stutent at Leon Guanajuato. Ramón studied the diffusion of a mixture of monomers and dumbbells in severe confinement, both theoretically and experimentally (Phys. Rev. E 94, 012608 (2016))
Andrea Llanas (undergraduated student short stay 2016). Andrea developed the technique of the recovery of optical parameters using as an standard a colloidal suspension comparing her experimental results with Mie's scattering theory. Andrea also analyzed the possibility of describing light propagation in a binary mixture of particles of different sizes (in collaboration with Beatriz Morales, FIUASLP).
María de Jesús Martínez (summer student 2013), currently Masters student at IFUASLP. Chuy made progress in David's Pine synthesis of colloidal clusters, but using UV radiated non-crosslinked particles instead of cross-linked particles.
Lisbeth Pérez Ocampo (summer student 2013), currently PhD student at León Guanajuato. Lis worked in the depletion problem, using a mixture of 1.5 micron and 0.2 micron particles, finding that bigger particles feels an attraction between them and glass plates.
Mariana Dorantes Gilardi (summer student 2013), currently Master student at CICESE. Mariana studied the electrophoretic phenomena in viscoelastic materials.
COLLABORATORS:
Prof. Jose Luis Arauz Lara, Institute of Physics, University of San Luis Potosí
Prof. Rolando Castillo, Institute of Physics, National University of México
Dr. Iván Santamaría Holek, School of Sciences, National University of México
Dr. Beatriz Morales Cruzado, School of Engineering, University of San Luis Potosí
Dr. Francisco Gerardo Pérez Gutiérrez, School of Engineering, University of San Luis Potosí
Dr. Ramón Castañeda Priego, Science and Engineering Division, University of Guanajuato
Dr. Alfredo Méndez Cabañas, Institute of Physics, University of San Luis Potosí
Dr. Ivan Guerrero Garcia, Institute of Physics, University of San Luis Potosí
Prof. Dr. Stefan U. Egelhaaf, Physik der weichen Materie, University of Dusseldorf, Germany
Dra. Vanesa Olivares Illana, Institute of Physics, University of San Luis Potosí
Dra. Susana Figueroa Gerstenmaier, Science and Engineering Division, Univertity of Guanajuato