In electrospray printing, the accumulation of electric charge on the target substrate plays an important role in governing the structure of the deposit. To better understand the effect of charge, we report on the use of two methods to measure the rate of charge accumulation and decay on dielectric substrates targeted with electrospray: ohmic dissipation (OhmD) and electrostatic force microscopy (EFM). The OhmD measurements were conducted on an assembly consisting of two different target materials: nylon and glass. The charge accumulation and decay were governed by the electrospray operating conditions, including spray time, flow rate, solution electrical conductivity, and the dielectric properties of the target. We found that the accumulation of charge influenced the electrospray mode in a transient way by decreasing the electric field strength between the emitter and the substrate. To complement the OhmD measurements, the charge accumulation and decay were measured at discrete spots on a silicon substrate coated with photoresist using EFM. These highly spatially resolved measurements revealed that while the electric charge was not distributed uniformly across the substrate, it still followed a similar decay trend as that obtained using the OhmD measurement. The results reported here will assist in understanding and predicting the structure of a deposit printed using electrospray.

在电喷雾印刷中，目标基板上电荷的积累在控制沉积物的结构方面起着重要作用。为了更好地了解电荷的影响，我们报告了使用两种方法来测量以电喷雾为目标的介电基片上电荷积累和衰减的速率：欧姆耗散（OhmD）和静电力显微镜（EFM）。OhmD测量是在由两种不同目标材料组成的组件上进行的：尼龙和玻璃。电荷的积累和衰减取决于电喷雾的工作条件，包括喷雾时间，流速，溶液电导率和靶材的介电性能。我们发现，电荷的积累通过降低发射极和基板之间的电场强度，以瞬态方式影响了电喷雾模式。为了补充OhmD测量，使用EFM在涂有光刻胶的硅基板上的离散点处测量了电荷积累和衰减。这些高度空间分辨的测量结果表明，尽管电荷在基板上分布不均匀，但仍遵循与使用OhmD测量获得的相似的衰减趋势。此处报告的结果将有助于理解和预测使用电喷雾打印的沉积物的结构。使用EFM在涂有光刻胶的硅基板上的离散点上测量电荷的积累和衰减。这些高度空间分辨的测量结果表明，尽管电荷在基板上分布不均匀，但仍遵循与使用OhmD测量获得的相似的衰减趋势。此处报告的结果将有助于理解和预测使用电喷雾打印的沉积物的结构。使用EFM在涂有光刻胶的硅基板上的离散点上测量电荷的积累和衰减。这些高度空间分辨的测量结果表明，尽管电荷在基板上分布不均匀，但仍遵循与使用OhmD测量获得的相似的衰减趋势。此处报告的结果将有助于理解和预测使用电喷雾打印的沉积物的结构。