## 1 Introduction  
Imparting porous architecture to macroscopic objects has been a key scientific subject for a long time [1; 2; 3; 4]. From then on, a plethora of porous materials have been synthesized and, among the others, polymer-based porous materials have gained much interest due to their easy processability and diversity of synthetic routes at our disposal [3; 4]. In addition, porous polymer materials have found many applications in several fields, e.g., gas storage and separation, controlled release of drugs, catalysis, and sensing [4; 5; 6; 7]. One subclass of porous polymer materials, known as monolithic polymer materials, is particularly promising due to some remarkable characteristics, i.e., variety of porosity, pore size, and many combinations of chemical functionalities by controlling precursors and chemistry during polymerization [8; 9; 10; 11; 12; 13; 14; 15; 16; 17; 18].  
Porous polymer monoliths are usually defined as rigid and continuous objects with an open cellular porous structure, which allows fluids to flow through. These are usually prepared by copolymerization of functional monomers and crosslinkers in presence of porogenic solvents/agents. Although this approach is proven solid and feasible, it still has some limitations once a multi-functional porous polymer monolith has to be prepared.  
Indeed, such functionalities are typically obtained starting from functional monomers whose functional groups are mainly lost within the dense polymer structure. Conversely, post-modification strategies of monolithics have been invoked to overcome these limitations, including post-processing chemical modification of monoliths such as epoxy groups of polymerized glycidyl methacrylate units [19; 20] or modification of the pore surface by grafting of functional polymer chains [21; 22; 23; 24; 25; 26; 27]. Albeit these approaches enable independent control over porous structure and surface chemistry, they require a complex post processing modification, which in turn requires a certain degree of control over the reaction conditions, making the process not very straightforward.  
On the other hand, the photoinitiated polymerization route towards porous polymer structures has been implemented in several studies [28; 29; 30; 31; 32; 33] where high internal phase emulsions were used as templates. Although using high internal phase emulsions brings several sought-after structural properties, such as high porosity and degree of pores interconnectivity, it also shows some drawbacks, such as poor mechanical strength and, more importantly, the polymer structure mainly acts as a support or scaffold for post-processing functionalization.  
Differently, this paper investigates the photoinitiated polymerization of low internal phase emulsion into porous monolithic materials featuring (i) interconnected meso-porosity, (ii) suitable Young' module, (iii) independent loading of the pores and polymer matrix without serious cross-contamination (controlled differential loading) with virtually any compatible materials of choice (polymers, nanostructures, biomolecules), and (iv) good processability.  
Monolithic porous materials in the shape of microneedles arrays have been the subject of intense research as transdermal drug delivery systems [34; 35; 36; 37; 38]. On the contrary, much less attention has been paid to their application as transdermal medical devices for personal healthcare monitoring [39; 40; 41]. The skin interstitial fluid shows a dynamic exchange of molecules with capillary blood vessels therefore it allows us to access a range of analytes in a continuous and mini-invasive manner [42]. For instance, the continuous measurement of the glucose levels present in the skin interstitial fluid may allow the continuous and mini-invasive monitoring of glycaemia in diabetic patients [43]. Bearing this in mind, we have tested the proposed procedure on the fabrication of microneedles arrays by replica molding and application in glucose monitoring.