Effects of Relative Humidity and Ambient Temperature on the Ballistic Delivery of Micro- Particles to Excised Porcine Skin  Mark Kendall, Stephen Rishworth, Fiona Carter, Thomas Mitchell  Journal of Investigative Dermatology  Volume 122, Issue 3, Pages 739-746 (March 2004) DOI: 10.1111/j.0022-202X.2004.22320.x Copyright © 2004 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 1 (a) Experimental and modelled particle penetration depths as a function of RH. Temperature was held constant at 25°C. (b) SC yield stresses obtained from quasi-static tensile tests byWildnauer et al (1971), and the calculated SC yield stresses required in the unified penetration model to obtain the ballistic penetration depths. Journal of Investigative Dermatology 2004 122, 739-746DOI: (10.1111/j.0022-202X.2004.22320.x) Copyright © 2004 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 2 (a) Experimental and modelled particle penetration depths as a function of the ambient temperature. RH was held constant at 15%. (b) SC yield stresses obtained from quasi-static tests byPapir et al (1975), and the calculated SC yield stresses required in the unified penetration model to obtain ballistic penetration depths. Journal of Investigative Dermatology 2004 122, 739-746DOI: (10.1111/j.0022-202X.2004.22320.x) Copyright © 2004 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 3 Schematic diagram of the hand-held contoured shock tube (CST) particle delivery device used in this study. Journal of Investigative Dermatology 2004 122, 739-746DOI: (10.1111/j.0022-202X.2004.22320.x) Copyright © 2004 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 4 Photomicrograph of a histology slide of gold particles delivered to porcine skin. Similar images were used to extract the particle penetration depths in the temperature and humidity variation experiments. The scale bar denotes 50 μm. Journal of Investigative Dermatology 2004 122, 739-746DOI: (10.1111/j.0022-202X.2004.22320.x) Copyright © 2004 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 5 Schematic diagram of the structure of the epidermis of mammalian skin (a), and the corresponding bilayer approximation of the epidermis used for the theoretical penetration model (b). Penetration Case A denotes particle delivery into the stratum corneum (dsc), whereas in Case B the stratum corneum is fully breached (tsc) and the final particle location is within the viable epidermis (dve). The impact velocity is vi, while the input velocity for the viable epidermis is vi, ve. (adapted from Fuchs and Raghavan, 2002) Journal of Investigative Dermatology 2004 122, 739-746DOI: (10.1111/j.0022-202X.2004.22320.x) Copyright © 2004 The Society for Investigative Dermatology, Inc Terms and Conditions