Shape memory polymer sensors for tracking cumulative environmental exposure

Abstract

Cornerstone Research Group Inc. (CRG) has developed environmental exposure tracking (EET) sensors using shape memory polymers (SMP) to monitor the degradation of perishable items, such as munitions, foods and beverages, or medicines, by measuring the cumulative exposure to temperature and moisture. SMPs are polymers whose qualities have been altered to give them dynamic shape "memory" properties. Under thermal or moisture stimuli, the SMP exhibits a radical change from a rigid thermoset to a highly flexible, elastomeric state. The dynamic response of the SMP can be tailored to match the degradation profile of the perishable item. SMP-based EET sensors require no digital memory or internal power supply and provide the capability of inexpensive, long-term life cycle monitoring of thermal and moisture exposure over time.This technology was developed through Phase I and Phase II SBIR efforts with the Navy. The emphasis of current research centers on transitioning SMP materials from the lab bench to a production environment. Here, CRG presents the commercialization progress of thermally-activated EET sensors, focusing on fabrication scale-up, process refinements, and quality control. In addition, progress on the development of vapor pressure-responsive SMP (VPR-SMP) will be discussed.

Sağlik Alaninda Kullanilan Akilli Poli̇merler

“…Dokular yakın IR'ye karşı transparan özellik göstermektedir. Yakın IR bölgesindeki ışığa cevap verebilen materyaller sayesinde tümörler görüntülenebilir (Jeong, 2002 (Snyder, 2010). Ayrıca akıllı kıyafet ve sensör uygulamalarından sağlık alanındaki kullanımlarına kadar oldukça geniş bir kullanım yelpazesi bulunur (Chun, 2007).…”

“…Şekil hafızalı polimer ve kompozit uygulamalarından oldukça geniş çaplı bir üretim yelpazesiyle karşılaşmaktayız (Snyder, 2010). Ayrıca akıllı kıyafet ve sensör uygulamalarından sağlık alanındaki kullanımlarına kadar oldukça geniş bir kullanım yelpazesi bulunur (Chun, 2007).…”

An Edible Humidity Indicator That Responds to Changes in Humidity Mechanically

“…Research on humidity tags remains sparse to date despite the importance of humidity control as discussed above. The majority of reported humidity tags are chemo-chromatic; hence, they respond to changes in humidity by changing their color ,, while other examples by virtue of geometric deformation have also been proposed. , …”

“…The majority of reported humidity tags are chemo-chromatic; hence, they respond to changes in humidity by changing their color 12,21,22 while other examples by virtue of geometric deformation have also been proposed. 23,24 Thompson et al 21 proposed a chemo-chromatic tag using cobalt chloride to estimate the water activity of dried products. The easy hydration and dehydration reaction between humidity shift.…”

Stimuli-Responsive Shapeshifting Mesoporous Silica Nanoparticles

“…One group of SRMs, referred to as shape change materials (SCMs), can alter their shape upon the presence of a particular stimulus. Among the extensively studied SCMs, polymers are the most important class due to their low density, low cost, and potential biocompatibility. , Although polymers have a wide range of applications in sensing , and drug delivery fields, , long-term reliability/durability still remains a challenge . An alternative approach could be the design of a silica-based SCM, which would potentially provide a more reliable system due to the relative robustness of silica. − …”