All opportunities

Offers : 14

Engineered BiomimEtic platforms to analyse the molecular and cellular role of Heparan Sulfate on bone morphogenetic protein 2

Mail Sélection

Start date : 1 October 2018

offer n° LMGP2018_12

CONTEXTE
The industrial development of biomaterials for bone tissue regeneration is steadily increasing due to socio-economical need for bone repair therapies especially caused by the aging of the population and improvement of the quality of life. A boost of bone repair can be achieved using potent osteoinductive proteins, named bone morphogenetic proteins (BMPs). In Europe, the clinical use of BMP2 has been approved. However, its inappropriate delivery from collagen sponges and its supraphysiologic doses led to adverse clinical effects(1). Thus, there is a crucial need to engineer innovative carrier materials to optimize and better control the delivered dose of BMP2. Understanding which are the molecular regulators of BMP2 activity during bone repair and studying the BMP2 presentation via the bone extracellular matrix is therefore essential for a future new generation of BMP2-delivering biomaterials. In tissues, native BMP2 is presented via the extracellular matrix (ECM) components. The role of these ECM components on the bioactivity of BMP2 is still under debate.
Up to now important questions remain unanswered on (i) how can the presentation of BMP2 by ECM components affect bone differentiation? (ii) what is the role of each of these components in this context (iii) what are the underlying molecular mechanisms?

Project description
We design surfaces — biomimetic platforms — that present some selected components of the ECM. On the biomimetic platforms we will graft ECM components as the glycosaminoglycan heparan sulfate, which is known to bind BMP2 and adhesion peptides (cyclic RGD) to permit cells spreading via cellular adhesion receptors: integrins
The group has shown that the bioactivity of BMP2 can be enhanced by integrins activation(2). With quartz crystal microbalance with dissipation monitoring (QCM-D) and spectroscopic ellipsometry, we will characterize the binding of each ECM components on the streptavidin-coated platforms (Fig 1) (3, 4). After the characterization of the molecular assembling, we will use these platforms for studying cellular adhesion and differentiation with molecular biology methods as immunofluorescence and/or western blots. We will compare the effect of BMP2, presented via immobilized heparan sulfate or directly immobilized via biotin–streptavidin on BMP2-mediated osteogenic/chondrogenic differentiation.

2018-2021_BiometicPlatforms

Related Publications
1. Zara JN, Siu RK, Zhang X, Shen J, Ngo R, Lee M, et al. High Doses of Bone Morphogenetic Protein 2 Induce Structurally Abnormal Bone and Inflammation In Vivo. Tissue engineering Part A. 2011;17(9-10):1389-99.
2. Fourel L, Valat A, Faurobert E, Guillot R, Bourrin-Reynard I, Ren K, et al. beta3 integrin-mediated spreading induced by matrix-bound BMP-2 controls Smad signaling in a stiffness-independent manner. The Journal of cell biology. 2016;212(6):693-706.
3. Migliorini E, Horn P, Haraszti T, Wegner S, Hiepen C, Knaus P, et al. Enhanced biological activity of BMP-2 bound to surface-grafted heparan sulfate. Advanced Biosystems. 2017;1(4):1600041.
4. Migliorini E, Thakar D, Sadir R, Pleiner T, Baleux F, Lortat-Jacob H, et al. Well-defined biomimetic surfaces to characterize glycosaminoglycan-mediated interactions on the molecular, supramolecular and cellular levels. Biomaterials. 2014;35(32):8903-15.

Background and skills expected
Only master student (M2R), engineer diplomat or equivalent (minimum 5 years of university studies plus six months practical experience in a research environment) are eligible. We will select student motivated to work in a multidisciplinary environment, at the interfaces between physics, chemistry and biology. Expert in surface chemistry/ or biochemistry with basic expertise in cellular biology would be appreciated. The candidate should be interested to travel to accomplish two or three mission abroad to partner laboratories.

  • Keywords : Engineering science, Life Sciences, Biotechnology, biophotonics, LMGP
  • Laboratory : LMGP
  • CEA code : LMGP2018_12
  • Contact : elisa.migliorini@grenoble-inp.fr

Study of the piezoelectric properties of ZnO based nanocomposites: application to energy harvesting for autonomous sensors

Mail Sélection

Start date : 28 May 2018

offer n° IMEPLaHC-04172018-CMNE

 Study of the piezoelectric properties of ZnO based nanocomposites: application to energy harvesting for autonomous sensors
IMEP-LaHC / MINATEC / Grenoble-France
DEADLINE FOR APPLICATION: MAY 28th 2018

Keywords:
Nanotechnologies, Nanowires, Piezoelectricity, AFM, Semiconductor Physics and technology.

Description of the project:
Semi-conductor piezoelectric nanowires (NWs) (of GaN or ZnO among others) have improved piezoelectric properties compared to thin films and bulk materials, because of their greater flexibility, their sensitivity to weaker forces, and also, due to an intrinsic improvement in their piezoelectric coefficients which has been identified by recent theoretical and experimental studies [1, 2].
The integration of these nanostructures into nanocomposites (formed of NWs embedded in a dielectric matrix) is interesting for different applications, mainly sensors and mechanical energy harvesters [3, 4]. Very recent theoretical studies from our team show that these nanocomposites can feature improved performance compared to thin films [5, 6]. However, the development of these applications is currently hampered by an incomplete understanding of coupling effects between internal stresses (mechanical aspect), material polarization (piezoelectric effect), as well as doping and free carrier charge modulation (semi-conductor aspect). At the nanoscale, nonlinear effects can also become important.

From the fundamental point of view, the thesis will aim to deepen the understanding of electromechanical phenomena at the nanoscale by taking into account screening effects by ionized dopants, free carriers and interface traps. Several other important effects will also be studied, such as mechanical and electromechanical non-linearity, especially the higher orders of the piezoelectric effect, or flexoelectric effect, which probably plays a very important role in the piezoelectric response of nanostructures. The thesis will focus on the properties of nanowires as such, but also when immersed in a dielectric matrix to form a nanocomposite. It will be possible to vary experimentally some key parameters such as the doping and dimensions of the nanowires.

The student will have at his disposal all the experimental and simulation facilities of the laboratory, as well as access to the PTA technological platform for the preparation of specific test structures (metallization of contacts, connections, flexible membranes for deflection, etc.). The nanowires will be developed at the IMEP-LaHC or will be accessible through different collaborations (LMGP, INL, Institute Néel …).

The PhD student will contribute to the development of characterization techniques. The IMEP-LaHC laboratory was a precursor in 2008 by developing methods for the qualitative characterization of the piezoelectric phenomenon on individual NWs of GaN, by measuring the potential generated when a controlled force is applied to the NW using an AFM tip [1]. These techniques have recently been modified to perform controlled current measurements [7]. They will be further developed during this thesis and correlated with more standard measurements (PFM, KFM) or Scanning Microwave Microscopy [8]. All these measurements have the advantage of being possibly realized on the same NW, and thus of being correlated with each other.

At the same time, thanks to an ongoing collaboration with IM2NP and ESRF, the PhD student will have access to novel in-operando characterization means to combine X-ray diffraction deformation measurement with near field measurement of current and surface potential under mechanical stress. Multi-physics simulations (analytical models, finite elements) will serve as a support for interpreting experimental results, backed on the expertise developed in the team.

The acquired understanding should allow the PhD student to reach the second objective of the thesis, which is a first step towards future exploitation, with the identification of optimization guidelines and the realization of research proof-of-concept devices, along recent experiences developed at IMEP-LaHC [9, 10]. This will allow the candidate to validate the interest of the concept for mechanical energy harvesting. The development of these devices and their optimization is part of a European project Convergence (H2020 / FlagERA 2017-2020), where the student will additionally benefit from a stimulating international environment with a combination of academic labs and industrial companies.

References:
[1] X. Xu, A. Potié, R. Songmuang, J.W. Lee, T. Baron, B. Salem and L. Montès, Nanotechnology 22 (2011)
[2] H. D. Espinosa, R. A. Bernal, M. Minary‐Jolandan, Adv. Mater. 24 (2012)
[3] S. Lee, R. Hinchet, Y. Lee, Y. Yang, Z. H. Lin, G. Ardila, et al., Adv. Func. Mater. 24 (2014)
[4] R. Hinchet, S. Lee, G. Ardila, L. Montès, M. Mouis, Z. L. Wang Adv. Funct. Mater. 24 (2014)
[5] R. Tao, G. Ardila, L. Montès, M. Mouis Nano Energy 14 (2015)
[6] R. Tao, M. Mouis, G. Ardila, Adv. Elec. Mat. 4 (2018)
[7] Y. S. Zhou, R. Hinchet, Y. Yang, G. Ardila, L.Montès, M. Mouis, Z. L. Wang, Adv. Mat. 25 (2013)
[8] K. Torigoe, M. Arita and T. Motooka, J. Appl. Phys. 112, 104325 (2012)
[9] S. Kannan, M. Parmar, R. Tao, G. Ardila, M. Mouis, J. of Physics: Conf. Ser. 773 (2016)
[10] R. Tao, G. Ardila, M. Parmar, L. Michaud, M. Mouis, Proc. of IEEE Eurosoi/ULIS (2017)

More information:
Knowledge and skills required:
It is desirable that the candidate has knowledge in one or more of these areas: semiconductor physics, finite element simulation, Atomic Force Microscopy (AFM), clean room techniques and associated characterizations (SEM, etc.). The grades and the rank as undergraduate and especially for the Master degree are a very important selection criterion for the doctoral school.

Location: IMEP-LaHC / Minatec / Grenoble, France

Doctoral school: EEATS (Electronics, Electrical engineering, Automatism, Signal processing), specialty NENT (Nano Electronics Nano Technologies).

Advisors:
Mireille MOUIS (Advisor) (mouis@minatec.grenble-inp.fr)
Gustavo ARDILA (Co-advisor) (ardilarg@minatec.grenoble-inp.fr)

About the laboratory:
IMEP-LAHC / MINATEC / Grenoble
IMEP-LAHC is located in the Innovation Center Minatec in Grenoble. The main research areas concern Microelectronic devices (especially CMOS, SOI), Nanotechnologies, Photonic and RF devices. It works in close partnership with several industrial groups (such as ST-Microelectronics, IBM, or Global Foundries), preindustrial institutes (such as LETI, LITEN, IMEC, or Tyndall), as well as SMEs (e.g. CEDRAT). The PhD thesis will be carried out within the group working on MicroNanoElectronic Devices / Nanostructures & Nanosystems. The student will have access to several technological (clean room) and characterization platforms.
Contacts:
Gustavo ARDILA (ardilarg@minatec.grenoble-inp.fr ) +33 (0)4.56.52.95.32

  • Keywords : Engineering science, Electronics and microelectronics - Optoelectronics, FMNT, IMEP-LaHc
  • Laboratory : FMNT / IMEP-LaHc
  • CEA code : IMEPLaHC-04172018-CMNE
  • Contact : ardilarg@minatec.grenoble-inp.fr

3D printed electronic for Molded Interconnected Devices (MID) dedicated to Internet of Things applications

Mail Sélection

Start date : 3 September 2018

offer n° IMEPLaHC-04112018-RFM

                                                                                            

 

 

 

Within the framework of a Chaire Industrielle d’Excellence MINT*, the PHD relies on a direct printing technology of functional inks on tridimensional objects coupled with a robotic system. Electronic circuits are built directly on top of the mechanical parts and take benefit from the 3D deposition freedom given by this additive manufacturing technology. Such a 3D electronic is so combined with the mechanical substrate that its mechatronic integration is enhanced.
The increase of connected products on the market is exponential, for IoT and Industrial-IoT applications, leading to innovative manufacturing technologies needs for mechatronic integration.

The Phd work is dedicated to 3D electronic printing of functional inks on mechanical thermoplastic products. Printing process will be settled and synchronized on the existing 6 axis robotic platform. Within a 1st step, the student must adapt the printing process of functional inks and conductive pastes for 3D deposition on thermoplastic parts. She/He will optimize the associated curing process as well.
The 2nd Phd target is devoted to electronic design and stacking architectures of components. The goal is to take advantage of the multi-materials printing potential of the technology in addition to the 3D geometry of the substrate. Conductive tracks and printed components will be characterized versus their properties, reliability, and ageing behavior. Those measurements will be conducted first on 2D thermoplastic substrates within LGP2 and IMEP-LAHC laboratories. Afterward, they will be deployed on 3D products within S-Mart.DS robotic platform. The student will then explore the possibilities offered by the 3D additive manufacturing process in terms of innovative electronic design and system architecture for IoT-Industrial applications.

Due to the multidisciplinary domains of the skills involved, the applicant will rely on the expertise of the members of the Chaire Industrielle d’Excellence MINT*:
­    LGP2 : laboratory of printed electronic on flexible substrates
­    IMEP-LAHC : laboratory of design and characterization of advanced electronic systems
­    S-MART DS : technological plateform dedicated to industrial engineering
­    Schneider Electric : industrial company leader in energy management

With general technical skills, the applicant background needs to encompass materials physics (rheology, physicochemistry), mechatronic and electronic (passive components, sensors, antenna), as well as mechanic and robotic (dimensional control, trajectory tracking).
Open and curious, she/he appeals to work within a multidisciplinary context. Proactive and autonomous, she/he is found of experimental work and is very adaptive to laboratory and industrial platform environments. Her/His human skills make her/him evolve serenely within the various team involved in the Chaire MINT. She/He must have the ability to easily write scientific reports (French language) and present her/his work to the Chaire’s members during Scientific committees.
English language is mandatory as the Phd student should attend international conferences and submit papers within major scientific journals.

Remuneration : 2200 € gross /month

Contact : Mme N. Reverdy-Bruas (Grenoble INP) : nadege.reverdy-bruas@pagora.grenoble-inp.fr
*http://fondation-grenoble-inp.fr/nos-actions/contribuer-developpement-recherche/chaire-mint/

  • Keywords : Engineering science, Electronics and microelectronics - Optoelectronics, FMNT, IMEP-LaHc
  • Laboratory : FMNT / IMEP-LaHc
  • CEA code : IMEPLaHC-04112018-RFM
  • Contact : nadege.reverdy-bruas@pagora.grenoble-inp.fr

Scalable Manufacturing of ZnO and TiO2 based biofouling-resistant nanostructured membranes for water purification

Mail Sélection

Start date : 1 October 2018

offer n° LMGP2018_11

Recrutment_PhD_Chair_riasseto
Context of the PhD grant:

This PhD grant is associated with the Chair of Excellence of the Nanoscience foundation awarded to Professor Daeyeon Lee (UPenn) about nanostructures for antibiofouling and antibacterial applications.

Context and position of the project on the international scale

Access to clean water is not assured for major swathes of humanity. In the last century, demand grew at twice the rate of the population. The United Nation as well as the US National Academy of Engineering has indeed identified providing access to clean water as one of the Grand Challenges of the 21st century. In the Malthusian catastrophe, nearly one-fifth of the world’s population lack access to clean water and a quarter of the population faces economic water shortages [1]. Membrane separations are promising alternatives to thermal separations for production of clean water because of their scalability and energy efficiency [2]. Water treatment reverse osmosis membranes have been implemented in some parts of the world (e.g., Israel) to give solutions to a small region, proving that membrane technology will play a major role in solving the water issue globally [3]. Although numerous advances in membrane technologies have been made, there are outstanding challenges that impede their widespread adoption across the world. We have identified three problems that could potentially be addressed by advances in nanoscience and technology:
1. Membrane separation is often limited by the trade-off between selectivity and permeability. Membranes that are very permeable (i.e., that give high flux) are not very selective and vice versa [4, 5].
2. Biofouling and growth of biofilms (attachment and proliferation of bacteria on surfaces) significantly compromise the performance of these membranes and cause major health hazards [6, 7].
3. Many membranes suffer from long-term stability/durability issues under prolonged usage. The membranes inevitably have to be cleaned periodically to remove biofilms and other contaminants. Chlorine-based bleach, which is the most common and effective agent, significantly damages the structural integrity of the membranes, compromising their durability [8].

Recent advances in nanostructured membranes present a versatile approach to overcoming challenges associated with trade-off between permeability and selectivity and achieving highly efficient water purification while preventing biofouling on the membrane surfaces [4, 5]. Previous studies have shown that nanoparticle-incorporated films and membranes can be used for antibacterial applications as well as efficient water purification [9]. For example, TiO2 nanoparticle-incorporated films have shown to exhibit excellent antibacterial properties [10]. Incorporation of silica nanoparticles in polymer matrix led to fabrication of separation membranes with simultaneous enhancement of permeability and selectivity [4, 5, 11]. Unfortunately, most current methods to generate such nanostructured coatings and membranes are suitable only for lab-scale production owing to complicated fabrication steps. A critical bottleneck is the lack of robust methods to enable the cost-effective/large-scale fabrication of nanostructured membranes while maintaining the precise control over their nanoscale structures. Such membranes are typically fabricated by incorporation of nanoparticles directly into the polymer solutions for membrane formation [12]. This approach is challenging due to unfavorable interactions between the polymers and nanoparticles that drive nanoparticle aggregation, compromising the membrane structure and properties [13].
It is thus critical to develop means to fabricate nanostructured composite membranes with properties designed for specific applications and with high durability in challenging conditions based on scalable methods. We propose to develop heat- or solvent-driven infiltration of polymers into the interstices of nanoparticle/nanowire packings (capillary rise infiltration (CaRI) [14, 15] and solventdriven infiltration of polymers (SIP) [16]) and solvent transfer-induced phase separation (STRIPS) of nanoparticle-containing ternary solutions to enable the scalable fabrication of nanocomposite membranes [17, 18].

Scientific Objectives:

Scalable Nanomanufacturing of Nanostructured Membranes for Clean Water
The main objectives of this PhD thesis will be to transform the manufacturing of nanostructured composite membranes to enable their production in a scalable process suitable for large scale, low-cost manufacturing. Along the way, the PhD student will isolate key features required to maintain the advantages of these membranes, and potentially amending the process parameters of the membrane synthesis to retain key features while reducing cost and
complication. The main aspects of this project are:
1. Development of nanostructured composite membranes with ZnO nanowires or TiO2 nanoparticles, based on polymer infiltration. To achieve this objective, we aim to understand the infiltration of polymer into the interstices between nanoparticles/nanowires via capillary rise infiltration (CaRI) or solvent-driven infiltration of polymers (SIP).
2. Development of nanostructured hollow fiber membranes with dense coatings of photocatalytic nanoparticles or photopolymerizable inorganic materials (i.e, TiO2 photoresist) via STRIPS. Membranes will be manufactured with photocatalytic nanomaterials (i.e., TiO2 or ZnO) to impart photocatalytic activity for anti-biofouling and self-cleaning membrane fabrications.
3. In collaboration with a postdoctoral researcher, the separation performance and antibacterial/antifouling properties of membranes will be tested. Formation of biofilms and adhesion of bacteria on membranes surfaces under flowing or quiescent conditions will be investigated as a function of the structure, surface roughness, composition and wettability of our membranes under UV (photocatalytic conditions) or in dark conditions.
Water purification performance of nanostructured membranes as well as their durability will be investigated.

Characterization of nanostructured thin films of ITO, GaN and TiO2 in the terahertz domain

Mail Sélection

Start date : 1 September 2018

offer n° IMEPLaHC-03272018-PHOTO

                                                                                                                                     

                                                                                      PhD position in optoelectronics:
                                            Characterization of nanostructured thin films of ITO, GaN and TiO2 in the terahertz domain

Large bandgap semiconductors, like ITO or TiO2, exhibit smart optoelectronics properties that make them widely used, for example as transparent electrodes in optoelectronics display devices. They are also involved in other applications, such as photo‐catalyzer in treatment of polluted water or air.
Recently, nanostructured films of these materials have been employed to increase the efficiency of solar ce lls, light emitting diodes, and water depollution kinetic.
For all these possible applications, the electrical properties of the layers, and more explicitly the dynamics of free carriers (electrons), have to be precisely measured and understood, regarding the fabrication process and therefore the microscopic structure and the composition of the material.
French National Research Agency (ANR) supports a 4‐years project in which IMEP‐LAHC in France and the National Tsing Hua University in Taiwan join their expertise and competences.
Two kinds of application are targeted:
‐ with ITO (bandgap 3.7~3.9 eV) and GaN (3.4 eV), the interest lies in their excellent conductivity properties and transparency in view of potential applications in display, solar cells or components for the THz waves for the former. GaN and related materials are also key materials for optoelectronics and high‐speed and high‐power electronics.
‐ regarding TiO2 (3.2 eV), the production of free carriers and their injection into water in contact will be studied, in view of understanding the processes involved in photo‐assisted water catalysis.
Samples will be designed and fabricated in Taiwan, and then characterized by using different terahertz time domain spectroscopy (THz‐TDS) techniques in France at IMEP‐LAHC (Le Bourget du Lac). In a first step, all the samples will be measured on a very broadband THz‐TDS system to determine their
transmission and complex optical constants from 0.15 THz to 15 THz. In a second step, we will optically excite the semiconductors by pumping them near their bandgap energy (UV range) and monitor the evolution of their THz transmission. This UV pump‐THz probe time‐resolved spectroscopy technique
will allow us to study the dynamics of photo‐generated free carriers within a time‐resolution of the order of few fs. Finally, in water catalysis, we will also investigate the sub‐ps response of the selvedge water layer in contact with UV excited TiO2 with an attenuated total reflection (ATR) THz‐TDS system.
The PhD student will be in charge of building the experimental setup using amplified femtosecond laser and performing the experiments. Skills in optics, semi‐conductors physics and optoelectronics, as well as a strong interest in applied research are expected. Visits at the Taiwanese partners are scheduled.

Contract duration: 36 months Remuneration: 1600 euros (Tax free)
Contact : Emilie Hérault, IMEP‐LAHC, Emilie.Herault@univ‐smb.fr
Frédéric Garet, IMEP‐LAHC, Frederic.Garet@univ‐smb.fr

More information
X