Surface Acoustic Wave or SAW-based micro-devices are studied extensively for highly sensitive and real-time physico-chemical or biochemical sensing platforms [FAN11, LAN08, ROC09 and references therein]. In particular, shear horizontal waves guided in a thin surface film (known Love waves), are of interest for liquid samples. After short introduction of a typical SAW structure, we present particular applications to the characterization of thin films and complex fluids adjacent to the sensitive part, as investigated at IMS Bordeaux Labs. Indeed, the SAW propagation in the device is very sensitive to mechanical changes at the interface, both mass and viscoelastic effects inducing variations of electrical parameters that can be measured experimentally. Comparison with simulation can permit an evaluation of a material's mechanical parameters at high frequency, whereas they are typically described for bulky samples at low frequency. These variations can then be interpreted as biological or physico-chemical phenomena involved. Application to probe thin films is typically of interest to characterize innovative materials used as sensitive coatings for specific (bio)chemical detection. They can be organic, inorganic or hybrid materials, including structured/2D/3D-materials, biomimetic or biological ones. We present various examples, among those, for instance, the characterization of effective surface of molecular imprinted polymers (aiming cancer biomarkers detection) [OMA13, LEB13], compared to mesoporous sol-gel films of silicon dioxide or titania [BLA14], when exposed to vapors. Among examples, is also the deposition of polyelectrolyte films, optimized with real-time monitoring, then followed by bacteria or microalgae immobilization and detection of heavy metals at concentration as low as 10–12 M [GAM14, TEK13]. Application to probe viscoelastic complex fluids was put to evidence while developing the mixing of microfluidics and SAW devices [RAI06]. For example, the influence of polymeric chains length highlighted the sensitivity to the emergence of molecular entanglements above a critical molecular weight [RAI10]. References [BLA14] L. Blanc, G. Tortissier, C. Boissière, C. Dejous, D. Rebière, Love wave characterization of mesoporous titania films, In New Sensors and Processing Chain, J.Wiley & Sons, Hoboken NJ, USA., chap.2, 2014. [FAN11] S. Fanget, S. Hentz, P. Puget, J. Arcamone, M. Matheron, E. Colinet, P. Andreucci, L. Duraffourg, Ed. Myers, M.L. Roukes, Gas sensors based on gravimetric detection—A review, Sens. Actuators B: Chemical, 160(1) 804, 2011. [GAM14] I. Gammoudi, L. Blanc, F. Moroté, C. Grauby-Heywang, C. Boissière, R. Kalfat, D. Rebière, T. Cohen-Bouhacina, C. Dejous, High sensitive mesoporous TiO2-coated Love wave device for heavy metal detection, Biosensors and Bioelectronics, 57 p162, 2014. [LAN08] K. Länge, B.E. Rapp, M. Rapp, Surface acoustic wave biosensors: a review, Anal Bioan Chem, 391 p1509, 2008. [LEB13] N. Lebal, H. Hallil, C. Dejous, B. Plano, A. Krstulja, R. Delépée, L. Agrofoglio, D. Rebière, Nucleosides analogs recognition by Molecularly Imprinted Polymer- coated Love wave sensor, Micro & nano Letters, 8(10) 563, 2013. [OMA13] N. Omar-Aouled, N. Lebal, H. Hallil, R. Delépée, L. Agrofoglio, D. Rebière, C. Dejous, Study of Gaseous Compounds Adsorption with a Love Wave Sensor Based on Molecularly Imprinted Polymeric Thin Film, Sensors & Transducers Journal, 149(2) 37, 2013. [RAI06] V. Raimbault, D. Rebière, C. Dejous, M. Guirardel, V. Conédéra, J. Pistré, High viscosity sensing using a love wave acoustic platform combined with a PDMS microfluidic chip, ECS Transactions, 4(1) 73, 2006. [RAI10] V. Raimbault, D. Rebière, C. Dejous, M. Guirardel, J.L. Lachaud, Molecular weight influence study of aqueous poly(ethylene glycol) solutions with a microfluidic Love wave sensor, Sensors and Actuators A, 144(1) 318, 2010. [ROC09] M.I. Rocha-Gaso,C. March-Iborra, Á. Montoya-Baides,A. Arnau-Vives, Surface Generated Acoustic Wave Biosensors for the Detection of Pathogens: A Review. Sensors, 9 p5740, 2009. [TEK13] N. Tekaya, I. Gammoudi, M. Braiek, H. Tarbague, F. Moroté, V. Raimbault, N. Sakly, D. Rebière, Hat. Ben Ouada, F. Lagarde, Haf. Ben Ouada, T. Cohen-Bouhacina, C. Dejous, N. Jaffrézic-Renault, Acoustic, electrochemical and microscopic characterization of interaction of Arthrospira plantensis biofilm and heavy metal ions, J. Env. Chem. Eng., doi : 10.1016/j.jece.2013.07.006.