Development of a micromechanical thermogravimetric tool for investigation of biominerals

生物矿物是开发新材料的灵感来源，因为它们具有独特的性质、层次组织和混合成分（有机-无机复合材料）。这种被捕获的材料在决定其内在特性方面起着重要作用。因此，必须测量有机化合物的确切含量和分布，并进一步与给定的特定性质（如机械）相关联。然而，这些测量受到数量/尺寸的限制，即mm-cm和/或bbb50 mg，以及使用经典的热重分析。本项目旨在开发和实现一种热重分析，能够分析质量小至1ng的微尺寸物体的有机含量，质量分辨率为1pg。对微尺寸的、单独选择的对象的直接分析将允许我们消除与批量分析相关的工件。这种分析技术是基于一个共振加热的微观结构（悬臂），在共振频率移位的情况下，将允许我们量化温度引起的质量变化（1pg）。在方法建立后，合成和天然caco3基生物矿物将被用作概念验证。有机质量含量与其分布之间的相关性（由扫描力显微镜确定）将被揭示。此外，我们的目标是发展以下目标：a)通过用生物分子功能化微器件可加热尖端并促进CaCO3在微器件上直接结晶，来原位监测晶体学过程（质量负载测定）。此外，将进行本地有机含量测定；b)与合作伙伴（Rao教授，印度理工学院）共同开发具有高q因子分辨率，均匀温度分布和定义样品平台的定制高性能微器件；c)在可加热微型装置上进行原位红外吸收测量，用于直接监测与有机影响无关的晶体相变（非晶晶体）（Thundat教授，加拿大阿尔伯塔大学）。

Biominerals are a source of inspiration for the development of new materials given their unique properties, hierarchical organization and hybrid composition (organic-inorganic composites). This trapped material plays an important role in determining its intrinsic properties. Thus, both the exact content and the distribution of organic compounds must be measured and further correlated to given specific property (e.g. mechanical). However, these measurements are limited by quantity/size constrains, i.e., mm-cm and/or >50 mg and to the use of classical thermogravimetric analysis. This project aims to develop and implement a thermogravimetric analysis capable of analyzing the organic content micro-sized objects with masses as small as 1 ng with mass resolution of 1pg. The direct analysis of microsized, individually selected objects will allow us to eliminate artifacts associated with bulk analysis. This analytic technique is based on a resonating heated microstructure (cantilever) that, upon resonance frequency shifts, will allow us to quantify temperature-induced mass changes (1pg). Upon methodology establishment, both synthetic and natural CaCO3-based biominerals will be used as proof-of-concept. A correlation between organic mass content and its distribution (determined by scanning force microscopy) will be revealed. Further, we aim to develop the following goals: a) in situ monitoring of crystallographic processes (mass loading determination) by functionalizing the microdevices heatable tips with biomolecules and promoting CaCO3 direct crystallization onto the microdevice. In addition local determination of organic content will be performed; b) development of a custom-made high performance microdevices with high Q-factors resolution, a uniform temperature distribution and a defined sample platform together with our cooperation partner (Prof. Rao, IIT, India); c) implementation of in situ IR-absorption measurements carried out on heatable microdevices for direct monitoring of crystal phase-transitions (amorphous-crystalline) not associated with an organic influence (Prof. Thundat, University Alberta, Canada).