1. New Polyester Biomaterials: Design of Shape Memory Surfaces and Particles Valerie S. Ashby, University of North Carolina at Chapel Hill, DMR 0706433 Present Materials: -Shape memory polymers (SMPs) are proving to be an attractive tool in biomedical applications such as self-tightening sutures, self-deploying stents and drug delivery vehicles. An example of an SMP responding to heat is shown in Fig. 1. The present materials possess macro SMP properties, where the entire bulk polymer changes shape in response to a stimulus. New Finding/Potential Applications: - We have recently reached an exciting finding, producing shape memory materials with nano- to micron-sized surface features that can be switched or erased when triggered with heat (Fig. 2). These new materials have potential impacts on surface adhesion, cellular response, drug delivery, tissue engineering, etc. Application/Materials Need: - To advance the applications above, there is a need for specifically designed SMPs that can be switched at the nanoscale, at controlled temperatures (e.g. body temperature), with varying stimuli (e.g. heat, light, etc.) and that contain reactive functional groups for later surface chemical modification. New Materials Design: - Based on our initial finding, we have designed several new SMP biomaterials that have easily tailored thermal and mechanical properties with reactive functional groups. To our knowledge, no examples that combine this set of properties with the ease of nanofabrication exist. These materials have been designed to have thermal switching temperatures that range from room temperature to 80 ° C. Furthermore, the surface functionality can be altered to include reactive alcohol and alkyne groups. Finally, the new polymers have been designed with dual switches, (heat and light) for further control over material response. SMP particles are presently being produced. Figure 1. MACRO Shape memory polymer recovery process 1-6 occurs in 6 sec at 64 °C. Scale Bar: 5 mm 1 2 3 456 Figure 2. NANO to MICRO Shape memory polymer recovery process Top row: Temporary 200 x 36 nm features (middle) imprinted on unpatterned surface (left) and thermally “erased” (right). Bottom row: Temporary 3 μm cubes (middle) imprinted on a 3 μm hex nut-patterned surface (left). Hex nut pattern recovered on heating (right). Scale Bars: 10 μm

2. New Polyester Biomaterials: Design of Shape Memory Surfaces and Particles Valerie S. Ashby, University of North Carolina at Chapel Hill, DMR 0706433 A. Summer Undergraduate Research Symposium Students Involved: 25 underrepresented minority rising juniors and seniors, visiting UNC for 10 weeks of summer research Program Goal: to help prepare undergraduates from across the country to earn doctoral degrees in STEM fields. Achievements: In the last year, 8 of the 12 participating rising seniors enrolled in STEM doctoral programs at the University of Nebraska, UNC-Chapel Hill, University of Michigan and George Washington, University of Pennsylvania and NC State. Collaborators: The PI is the director of this program and collaborates with several departments and faculty on campus in this effort. B. Graduate Student Crosstalk Students Involved: Approximately 25-30 underrepresented STEM graduate students from UNC, NC State and NC A&T and surrounding universities attend the Crosstalk workshops held throughout the year. Program Goal: to provide students with information, networks and a cohort that are critical to their successful completion of the PhD and entry into industrial and academic research careers Achievements: The successful cohort building, sharing of information and resources has led to the doctoral graduation rates of those who participate in these and other activities throughout their years in graduate school earning doctorates at a rate of approximately 85%. 10% of those who do not complete doctoral degrees complete master’s degrees. This compares with the UNC average graduation rate across campus for all student entering doctoral programs of 60- 65%. Collaborators: The PI along with the Asst. Dean of the graduate school at NCSU and the associate provost at NC A&T coordinate these activities. A B