In optogenetic studies, the brain is exposed to high-power light sources and inadequate power density or exposure time can cause cell damage from overheating (typically temperature increasing of 2 ${}^{\circ }$ C). In order to overcome overheating issues in optogenetics, this paper presents a neural tool capable of assessing tissue temperature over time, combined with the capability of electrical recording and optical stimulation. A silicon-based 8 mm long probe was manufactured to reach deep neural structures. The final proof-of-concept device comprises a double-sided function: on one side, an optrode with LED-based stimulation and platinum (Pt) recording points; and, on the opposite side, a Pt-based thin-film thermoresistance (RTD) for temperature assessing in the photostimulation site surroundings. Pt thin-films for tissue interface were chosen due to its biocompatibility and thermal linearity. A single-shaft probe is demonstrated for integration in a 3D probe array. A 3D probe array will reduce the distance between the thermal sensor and the heating source. Results show good recording and optical features, with average impedance magnitude of 371 k $\mathsf{\Omega }$ , at 1 kHz, and optical power of 1.2 mW·mm ${}^{-2}$ (at 470 nm), respectively. The manufactured RTD showed resolution of 0.2 ${}^{\circ }$ C at 37 ${}^{\circ }$ C (normal body temperature). Overall, the results show a device capable of meeting the requirements of a neural interface for recording/stimulating of neural activity and monitoring temperature profile of the photostimulation site surroundings, which suggests a promising tool for neuroscience research filed.

This paper presents a simple micromachining process to fabricate 2-D devices consisting of up to 20-mm-long shafts for neural applications. The manufacturing technology was mainly based on traditional blade dicing, normally used for wafers individualization into chips/devices in semiconductor and micro-electro-mechanical systems technologies. Here, it is demonstrated how a fully mechanical cutting technology is applied to the successful manufacture of challenging components with high-aspect ratio devices up to 41:1. Several other aspect ratio shafts (lengths varying between 5 and 20 mm) were produced and tested, for both the single-shaft and array devices. Mechanical characterization tests evaluated the devices robustness. Compressive strength tests for single-shaft 20-mm long shafts showed good longitudinal resistance to fracture, withstanding 28 N before breaking. Longitudinal forces play the key role while implanting the shaft inside the brain. Moreover, it was measured the load required to implant and extract 20-mm five-shaft array devices in two different mediums: 0.6% agar gel and calf cadaver brain. Maximum average insertion forces were 23 and 59 mN per shaft at 180 mm.min⁻¹ for agar and cadaver brain mediums, respectively. Overall, by enhancing the performance of a purely mechanical machining tool, the micro manufacture of high-aspect ratio silicon shafts for neuroscience applications was demonstrated. [2018-0072]

The red macroalgae Palmaria palmata is rich in protein and bioactive compounds and has been identified as a promising dietary ingredient for aquafeeds, with the potential to partially replace selected plant-based feed components. A digestibility trial and a growth trial were conducted to evaluate the potential of untreated and pretreated P. palmata as feed ingredients for juvenile European seabass ( Dicentrarchus labrax ), with initial body weights of 63.2 g and 38.0 g, respectively. Five diets were formulated: a control diet without macroalgae, and four diets including either 7.5% or 15% of untreated and pretreated P. palmata , replacing plant ingredients. The apparent digestibility coefficients of dry matter, crude protein, lipids, and gross energy did not differ among diets. The dietary inclusion of up to 15% P. palmata significantly increased the growth performance and feed efficiency compared to the control diet, without affecting nutrient digestibility, digestive enzyme activities, plasma metabolites, or whole-body composition of the fish. The pretreatment applied to P. palmata significantly increased soluble protein content and decreased neutral detergent fiber, but did not further improve growth or feed efficiency. Overall, these results indicate that up to 15% P. palmata can be successfully incorporated into the diets of juvenile European seabass, improving growth performance without adverse effects on nutrient digestibility. Further work is required to evaluate the functional properties and implications for fish health of P. palmata as well as to assess its economic viability within commercial aquafeed formulations.